NOTES 

ON 

POWER  PLANT  DESIGN 


PREPARED 

FOR  THE  USE  OF  STUDENTS  IN  THE 

MECHANICAL  ENGINEERING 

DEPARTMENT 

OF  THE 


MASSACHUSETTS 
INSTITUTE  OF  TECHNOLOGY 


EDWARD  F.  MILLER 

\  \ 


1915 


COPYRIGHT,  1916 

BY 
EDWARD  F.  MILLER 


INTRODUCTION 


An  attempt  has  been  made  to  assemble  here,  in  condensed  form,  data  which  it  is  believed 
will  be  of  assistance  to  one  beginning  on  the  laying  out  of  a  power  plant. 

Some  of  the  material  has  been  taken  from  articles  which  have  appeared  either  in  the  Trans- 
actions of  the  American  Society  of  Mechanical  Engineers  or  in  the  engineering  periodicals. 
Abstracts  have  also  been  made  from  Gebhardt's  Steam  Power  Plant  Engineering,  from  Koester's 
Steam  Electric  Power  Plants,  from  Peabody  and  Miller's  Steam  Boilers,  from  Illustrations  of 
Steam  Engines,  Steam  Turbines,  etc.,  from  trade  catalogues  and  from  publications  gotten  out 
by  manufacturers  of  the  different  pieces  of  apparatus  which  enter  into  the  equipment  of  a  power 
plant. 

E.  F.  M. 


TABLE  OF  CONTENTS 


DISTRIBUTION  OF  HEAT 5,  6 

BOILERS 7-15 

Methods  of  supporting;  dimensions  of;  flues  for;  using  fuel  oil;  stack  for  boilers  using  fuel  oil. 

ECONOMIZERS 16-23 

Calculation  of  size  of;  tables  of  dimensions  of. 

MECHANICAL  STOKERS 24-25 

CHIMNEYS,  FLUES  AND  DRAUGHT 26-29 

FEED  PUMPS  —  VENTURI  METER 29-33 

ENGINES 34-49 

Steam  Consumption  of;  calculation  of  power  of;  cylinder  efficiency  of  steam  engines  and  steam 
turbines;  Rankine  efficiency  and  cylinder  efficiency;  calculation  of  bleeder  type  of  engine 
or  turbine;  bleeding  steam;  comparison  of  engines  and  turbines  and  water  rate  of  small  tur- 
bines; general  dimensions  of  and  floor  space  required  by  engines. 

CONDENSERS  AND  ACCESSORIES 50-68 

Surface;  jet;  air  pumps;  dry  air  pumps;  circulating  pumps;  exhaust  relief  valves. 

FLOW  OF  STEAM  IN  PIPES 69-71 

FEED  WATER  HEATERS 72-75 

COOLING  TOWERS 76-80 

Calculation  of;  power  required  by  fan;  extra  work  put  on  circulating  pump. 

SPRAY  NOZZLES 80-81 

CENTRIFUGAL  PUMPS 82-90 

Characteristics  of;  friction  of  water  in  pipes. 

COAL  HANDLING  AND  COAL  BUNKERS 91-106 

Pivoted  bucket  conveyors;  belt  conveyors,  scraper  conveyor;  power  required;  crushers;  parabolic 
bins. 

FOUNDATIONS,  CONCRETE  FLOORS,  WALLS 106-125 

COSTS 126-139 

Cost  of  various  items  entering  into  power  house  construction  and  into  equipment  of  power 
house;  cost  of  operation  and  distribution  of  operating  costs;  failure  to  make  guarantees  as 
to  performance  as  affecting  cost. 

PIPING  AND  PIPE  FITTINGS 140-156 

Dimensions  of  fittings;  list  price  and  discounts;  cast  iron  pipe  for  water  work. 

PIPE  COVERING 157-159 

Cost  of;  insulating  value  of  different  thickness  of;  covering  for  flues  and  for  boiler  drums, 

SPECIFICATIONS 160-178 

Surface  condenser;  hot  well  pump;  dry  vacuum  pump;  low  pressure  turbine;  direct  acting  boiler 
feed  pump;  automatic  pump  and  receiver;  horizontal  cross  compound  non-condensing  Cor- 
liss engine;  steam  driven  centrifugal  pumping  unit;  motor  driven  centrifugal  pumping  unit. 

CUTS  OF  STATIONS    ,  * 179-185 


DISTRIBUTION    OF    HEAT 


It  is  generally  known  that  but  a  small  proportion  of  the  heat  of  the  coal  burned  in  a  power 
plant  goes  into  power. 

In  cases  where  there  is  a  large  demand  for  steam  for  heating  during  eight  months  of  the  year 
the  exhaust  steam  from  the  engines  or  turbines  used  for  power  or  lights  may  be  saved  by 
utilizing  this  steam  in  the  heating  system. 

Under  such  conditions  the  cost  of  power  for  the  period  of  heating  is  low  and  during  this 
period  the  economy  of  the  engine  is  of  little  moment  provided  there  is  never  a  surplus  of  exhaust 
steam.  During  the  remaining  four  months  when  no  heat  is  required,  the  economy  of  the  engine 
is  of  importance. 

Under  all  conditions  the  efficiency  of  the  boiler  affects  the  cost  of  operation. 

The  distribution  of  heat  throughout  a  plant  may  be  illustrated  by  the  two  cases  worked 
out  below. 

CASE  I 

Engine  uses  30  Ibs.  steam,  100  Ibs.  gage  per  Brake  Horse  Power  per  hour;  exhausting  out- 
board. 

Feed  water  enters  boiler  at  70°. 
No  heater  installed. 

Per  Cent  by  Weight  B.  T.  U. 

Engine     30  (1187-38)     ...........  .    .      .         100  34,470 

Feed  Pump     .6  (1187  -38)  ............  2  689 

Drips,  radiation     .45  (1187  -38)     ........      .      .          1.5  517 

35,676 
One  horse  power  hour  corresponds  to   .....      ..........        2,545 

2  545 

The  thermal  efficiency  of  the  engine  end   =  ^         r  =  .0713 

o5,b7o 

The  boiler  supplying  steam  we  will  assume  to  use  a  coal  of  14,600  B.T.  U.tothelb.  and  that  the 

Per  Cent 
Per  Cent  of  heat  of  coal  utilized  by  boiler  is  ..........  .......  68 

Per  Cent  lost  by  radiation,  loss  of  coal  through  grate,  etc.  is    ........  10 

Per  Cent  of  heat  of  coal  carried  off  by  flue  gas  is       ...........  22 

100 
14,600  x.68  =  9,928  B.  T.  U. 


or 

Coal  per  Brake  Horse  Power  Hour   =  --SO-  =  3.594  Ibs. 


The  overall  efficiency  of  the  plant  is  .0713  x.68  =  .0485 

2  545 
y  dividing  3  594^  14500  =  '°485 

3.594  x  14,600  =  52,470  B.  T.  U.  per  I.  H.  P.  hour. 


2  545 
which  may  be  found  by  dividing  3  594^  14500  =  '°485 


NOTES  ON  POWER  PLANT  DESIGN 


CASE  n 

Modern  Turbine  or  Engine  Plant  using  Superheated  Steam  at  high  pressure  with  28"  vacuum 
in  condenser.  Economizer,  Primary  and  Secondary  heaters  installed.  Coal  14,600  B.  T.  U. 
Der  Ib. 

Combined  Boiler  and  Economizer  Efficiency   =  76  per  cent. 

Boiler  pressure  184  Ibs.  absolute,  superheat  52°  F.     Back  pressure  1  Ib.  absolute. 

Feed  water  enters  primary  heater  at  65°;  leaves  at  88°;  enters  secondary  at  88°;  leaves  at 
150°;  enters  economizer  at  150°;  leaves  at  300°. 

Engine  or  turbine  requires  12.1  Ibs.  per  I.  H.  P.  hr.  or  12.1  -=-.93  =  13  Ibs.  per  brake  horse 
power  hour. 

Per  Cent  by  Weight 


Engine  or  turbine  13  (1228.6  -118) 

Feed  Pump 

Circulating  Pump  for  Condenser   . 

Wet  Pump 

Dry  Vacuum  Pump        .... 
Drips,  radiation,  etc 


100 
1.5 
3.0 
1.5 
1.5 
1.5 


B.T.U. 

14,438 
216 
432 
216 
216 
216 

15,734 


2  545 

r  =  .1617  the  engine  efficiency  assuming  feed  pump  part  of  engine  room  outfit. 
15,734 


.1617  x. 76  =  overall  efficiency  =  .1229 

The  auxiliaries  use  9%  of  engine  steam,  or  .09  x!3  =1.17  Ibs.  hr.  per  engine  horse  power. 
There  is  consequently  13  +1.17  =  14.17  Ibs.  passing  through  primary  and  secondary  heater  and 
through  economizer  per  13  Ibs.  supplied  to  engine. 

(88  -  65)  14.17  =  326  B.  T.  U.  recovered  in  Primary  heater. 

(150  -  88)  14.17  =  878  B.  T.  U.  recovered  in  Secondary  heater. 

The  total  coal  per  engine  horse  power  output  hr.'is 


15,734 


=  1.418  Ibs. 


14,600  x.76 

1.418  x  14,600  =  20,702  B.  T.  U.  supplied  by  coal  per  engine  H.  P.  output. 

20,702  x.l  229    =  2,545  B.  T.  U.  put  into  work  or  one  horse  power  hour. 

Had  the  primary  and  secondary  heaters  not  been  supplied  there  would  have  been  required 


additional  coal  by  an  amount  equal  to 


=  -109  Ibs.  making  the  coal  consumption  per 


5247O  B.TU  from  Coal 


35676  -f-o  Engine   and  Aux.  -^ 

3477O  to  Engine  * 
207O3  B.T.U  from  Coa/^ 

15734-  to  Engine  and  Aux.^ 

14-4-38  / 

~O  Engine  ~* 

\ 

ll 
H 
ll 

II 

ll 

254-5 

engine  H.  P.  hr.  =  1.528  Ibs. 

The  results  of  these  two  calculations  have  been  plotted 
in  Fig.  1,  the  area  of  the  small  square  in  each  case  repre- 
senting the  heat  units  to  be  supplied  for  one  horse  power 
hour  output.  The  full  lines  represent  Case  I  and  the 
dotted  lines  Case  II. 

The  heat  exhausted  outboard  per  horse  power  hour  is  for 
Case  I  35,676-2,545  =  33,131  B.  T.  U. 

The  heat  exhausted  to  the  condenser  in  Case  II  is 
14,438  -  1,545  -  326  =  11,567  B.  T.  U.  The  2,545  being 
the  amount  put  into  work  and  the  326  that  transferred  to 
the  feed  water  in  the  primary  heater. 

Many  plants  like  that  cited  in  Case  I  with  constantly 
growing  demands  for  power,  have  overloaded  engines,  and 
boilers  which  cannot  be  run  at  increased  pressures. 

Often  times  if  condensing  water  be  available  a  low  pres- 
sure turbine  may  be  installed  and  the  exhaust  of  the 
engine  at  from  1  to  5  Ibs.  gage  pressure  passed  through  the 


NOTES  ON  POWER  PLANT  DESIGN  7 

turbine  and  additional  power  amounting  to  from  50  to  80  per  cent  of  the  engine  power  obtained 
from  the  exhaust  steam. 

In  general  an  engine  designed  to  run  non-condensing  is  not  made  sufficiently  strong  and  the 
bearing  surfaces  are  not  large  enough  to  stand  the  extra  load  brought  to  the  parts  when  the  engine 
is  run  condensing. 


BOILERS 

With  few  exceptions  every  large  power  plant  where  the  units  are  steam  driven,  is  equipped 
with  some  form  of  water  tube  boiler.  This  type  is  selected  (1)  because  large  powers  can  be  obtained 
from  single  units,  (2)  because  of  the  saving  in  floor  space  over  that  of  any  other  type  suitable  for 
large  power  houses  and  (3)  because  high  steam  pressures  in  large  units  can  be  carried  without  any 
appreciable  thickening  of  the  metal  through  which  the  heat  of  the  fire  is  transmitted. 

A  plant  which  is  to  be  kept  in  continuous  operation  should  have  a  sufficient  number  of  units 
so  that  with  one  laid  off  for  repairs  the  other  units  are  able  to  carry  the  entire  load. 

Hand  fired  boilers  working  with  natural  draft  can  be  run  33  per  cent  above  their  rating,  with- 
out difficulty,  provided  the  draft  at  the  smoke  outlet  at  normal  rating  is  at  least  .5"  of  water. 

Stoker  fired  boilers  working  either  with  forced  draft,  induced  draft  or  with  both  forced  and 
induced  draft  may  be  run  at  times  of  peak  load  at  300  per  cent  of  their  rating.  In  recent  years 
the  boilers  in  nearly  all  of  the  power  stations  have  been  planned  to  develop  from  150  to  200  per 
cent  of  their  rating  during  ordinary  running,  and 'even  higher  than  the  figures  given  in  times  of 
emergency. 

But  little  loss  in  thermal  efficiency,  results  from  forcing  a  boiler  to  150  per  cent  of  its  rating. 

When  boilers  are  supplied  with  attached  superheaters  it  is  not  advisable  to  have  any  possibility 
of  a  large  amount  of  saturated  steam  being  drawn  from  the  drums  of  the  boiler  as  such  a  proce- 
dure would  result  in  the  burning  out  of  the  superheater. 

Boilers  rated  400  to  600  H.  P.  cost  per  H.  P.,  erected  on  foundations  provided  by  the  purchaser, 
from  $16.50  to  $17.50;  with  attached  superheater,  the  price  increases  from  $1.00  to  $1.50  per  H.  P. 

If  the  demand  on  a  boiler  plant  amounted  to  3600  H.  P.  and  2000  H.  P.  were  installed,  the 
boilers  running  180  per  cent  of  their  rating,  the  reduction  in  first  cost  would  amount  to  ($16.50  + 
$1.50)  x!600  =  $28,800.  Taking  interest,  taxes,  insurance,  repairs  and  depreciation  as  13  per 
cent,  the  saving  on  overhead  charge  would  amount  to  .13  x  28,800  =  $3,744.  Any  slight  loss 
in  economy  due  to  forcing  the  boilers  would  be  more  than  offset  by  the  reduced  overhead  on  the 
building  due  to  the  smaller  boiler  room  required. 

Water  tube  boilers  are  given  a  nominal  rating  on  a  basis  of  10  sq.  ft.  of  heating  surface  per 
boiler  horse  power. 

Tables  giving  some  general  dimensions  of  the  Stirling,  Heine  and  Babcock  and  Wilcox  boilers 
follow. 

These  may  be  useful  in  getting  general  overall  dimensions,  weights,  etc.  It  is  evident  that 
any  of  these  boilers  may  be  modified  within  certain  limits. 

As  an  illustration  suppose  it  is  found  advisable  to  put  in  a  B.  &  W.  boiler  27  sections  wide, 
14  tubes  high,  tubes  18  ft.  long.  What  would  be  the  increase  in  width  and  in  height  over  a  boiler 
21  wide  and  9  high. 

The  width  increases  approximately  7"  per  section  and  the  height  approximately  6"  per  tube, 
making  the  width  and  height  of  the  boiler  19'  -  6"  and  18'  —  3"  respectively. 

With  4"  tubes  the  heating  surface  added  per  tube  is 

18'  x4  x  3.1416 

-^—      -  =  18.85  sq.  ft. 

I  _ 

7& 

The/ 80  tubes  add3566  sq.  ft.  orj57  H.  P.,  making  the  rating357  +  396  =  453  H.  P. 

It  musri  be  remembered  that  adding  heating  surface  does  not  necessarily  increase  the  power 
of  a  boiler;  the  grate  surface  must  be  increased  in  the  proper  proportion  at  the  same  time.  Roughly 
a  sq.  ft.  of  grate  is  to  be  added  for  two  18  ft.  tubes. 


8  NOTES  ON  POWER  PLANT  DESIGN 


HEINE  WATER  TUBE  BOILER 

This  boiler  requires  a  space  at  the  back  as  it  is  cleaned  from  the  ends.  Any  number  of  boilers 
of  this  type  can  be  set  side  by  side. 

The  space  in  front  of  the  boiler  should  be  sufficient  to  allow  of  the  renewal  of  a  tube. 

The  length  of  setting  from  fire  front  to  rear  of  brickwork  is  always  1  foot  4  inches  longer  than 
the  length  of  the  tubes,  for  instance,  the  setting  of  a  90  horse-power  boiler  is  17  feet  4  inches  long 
and  a  101  horse-power  boiler  is  19  feet  4  inches  long.  The  shell  with  manhead  extends  about  15 
inches  beyond  rear  of  setting,  so  that  if  possible  a  4-foot  space  should  be  allowed  behind  the  setting 
for  access  to  same.  In  special  cases  the  manhole  is  placed  in  the  front  head,  or  an  opening  may 
be  made  in  the  building  wall  opposite  manhole,  in  which  case  2  feet  behind  setting  will  be  sufficient, 
The  width  of  setting  may  be  determined  by  adding  the  thickness  of  brick  walls  to  the  width  of 
furnace.  Thus,  three  101  horse-power  boilers  in  a  battery,  with  19  inches  side  and  28  inches  divi- 
sion walls,  will  be  19['  +  53"  +  28"  +  53"  +  28"  +  53"  +  19"  =  21'  1".  Existing  walls  may  be 
utilized  where  space  is  limited,  and  the  outside  walls  here  reduced  to  a  furnace  lining  9  or  10  inches 
thick. 

The  grate-surface  given  for  bituminous  coal  is  such  that  the  rating  may  be  easily  developed 
with  a  }/2-inch  draught  at  the  smoke  outlet.  The  grate  area  given  for  anthracite  pea  coal  is  that 
necessary  in  order  to  develop  the  rating  of  the  boiler  with  V^-inch  draught  at  the  smoke  outlet. 
For  convenience  of  handling  it  is  advisable  to  limit  the  grate  length  for  anthracite  coal  to  7  feet 
6  inches.  Where  this  does  not  give  area  enough  for  the  desired  maximum  capacity  it  is  necessary 
to  increase  the  draught.  Standard  grate  lengths  are  6  feet  6  inches,  7  feet  and  7  feet  6  inches. 

Safety-valves  are  provided  as  required  to  meet  local  inspection  laws. 


NOTES  ON  POWER  PLANT  DESIGN 


HEINE  WATER-TUBE  BOILERS 


Tubes  3  1/2" 

Shells 

Steam   Outlet 

Square 

Horse- 

Feet 

Diameter 

Height  of 

Diam. 

power 

Heating 
surface 

Height  of                 Center  Line 
Flange  Above            Above  Floor 

Feed-pipe 

No.     Length 

No.          Diam.       Length 

Diam.           Floor  Level              Level  Specia  1 

1               Ins.      Ft.     Ins. 

Ins.              Ft.       Ins.                  Ft.       Ins. 

Ins. 

90 

903 

53         16 

for            36         19     41/2 

4                 11         71/2                  9          91/2 

1% 

101 

1010 

53         18 

all            36         21     4i/2 

4                 11         71/2                  9          91/2 

lfl 

113 

1130 

68         16 

Horse           36         19     4»/2 

4                  12         21/2                  10           41/2 

126 

1263 

68         18 

Power          36         21     4V2 

4                  12         21/2                  10           41/2 

1  V4 

127 

1273 

77         16 

36         19     4  1/2 

5                  12         21/2                  10           41/2 

l  Vi 

143 

1424 

77         18 

36         21     41/2 

5                  12         21/2                  10           41/2 

1  V2 

153 

•     1533 

94         16 

36         19     4  1/2 

5                  12         91/2                  10         111/2 

11/2 

171 

1714 

94         18 

36         21     4Vi 

5                  12         91/2                  10         111/2 

1% 

142 

1420 

86         16 

42         19     61/2 

5                  12         81/2                  10         10 

11/2 

158 

1588 

86         18 

42         21     6i/2 

5                  12         81/2          •        10         10 

1% 

170 

1708 

105         16 

42         19     61/2 

5                  13         31/2                  11           5 

11/2 

191 

1911 

105         18 

42         21     61/2 

5                  13         31/2                  11           5 

11/2 

156 
175 

1564 
1749 

95         16 
95         18 

42          19     61/2 
42         21     61/2 

5                  12         81/2                  10         10 
5                  12         81/2                  10         10 

11/2 

188 

1883 

116         16 

42         19     61/2 

5                  13         31/2                  11           5 

1  1/2 

210 

2106 

116         18 

42         21     6i/2 

5                  13         31/2                  11           5 

11/2 

171 

1716 

104         16 

48         19     91/4 

6                  13         21/2                  11           91/2 

2 

192 

1920 

104          18 

48         21     91/4 

6                  13         21/2                  11           91/2 

2 

206 

2061 

127         16 

48         19     9  1/4 

6                  14         21/2                  12           7% 

2 

230 

2306 

127         18 

48         21     91/4 

6                  14         21/2                  12           71/2 

2 

224 

2244 

138         16 

48         19     91/4 

6                  14         21/2                  12           71/2 

2 

250 

2508 

138         18 

48         21     91/4 

6                  14         21A                  12           71/2 

2 

262 

2621 

163         16 

48         19     91/4 

6                  14         BU                  13           21/2 

2 

293 

2931 

163         18 

48         21     91/4 

6                  14         91/2                  13           21/2 

2 

241 

2417 

149         16 

48         19    91/4 

6                  14         6                      12         10 

2 

270 

2702 

149         18 

48        21     91/4 

6                  14         6                      12         10 

2 

282 

2826 

176         16 

48         19    9  1/4 

6                  15         1                      13           5 

2 

316 

3160 

176         18 

48        21     91/4 

6                  15         1                      13           5 

2 

258 

2586 

160         16 

48         19    9  1/2 

8                  14         61/2                  12         10  1/2 

2 

289 

2892 

160         18 

48         21     91/2 

8                  14         61/2                  12         10  1/2 

2 

302 

3024 

189         16 

48         19    9  1/2 

8                  15          iyz                  13           51/2 

2 

338 

3383 

189         18 

48         21     91/2 

8                  15         11/2                  13           51/2 

2 

Grates 

Space    Occupied 

Blowoff 

Bituminous 

Anthracite 

Standard  Setting 
Height                  Height 

Special  Settng 
Height 

Low  Ceilings 
Height 

Cocks, 

Coal 

Pea  Coal 

over                        over 

over 

over 

1  V4" 
Diam. 

Furnace 
Width 

Length      Area 

Length           Area 

Safety-               Breeching 
Valve 

Shell 
at  Front 

Breeching 

No. 

Ft.   Ins. 

Ft.   Ins.  Sq.  Ft. 

Ft.  Ins.         Sq.  Ft. 

Ft.  Ins.                   Ft.  Ins. 

Ft.  Ins. 

Ft.  Ins. 

2 

4       5 

4     6         20.3 

4       71/2         20.4 

13      4%                 12       8 

10     10 

11       2 

2 

4       5 

5     0         22.5 

5       21/z         23.0 

2 

4       5 

5     0         22.5 

5     10             25.7 

13     111/2                 13       4 

11       5 

11     11 

2 

4       5 

5     6         24.7 

6       51/2         28.6 

2 

5       0 

5     0         25.4 

5       9             28.8 

13     11%                 13       4 

11       5 

11     11 

2 

5       0 

5     6         27.9 

6       6             32  .  5 

2 

5       0 

60         30.4 

6     11              34.7 

14       61/2                 13     11 

12       0 

12       7 

2 

5       0 

66         32.9 

7       9            38  .  8 

2 

5       7 

5     0         28.4 

59             32  .  2 

14       7i/2                 13      9 

11     10  1/2 

12       6 

2 

5       7 

5     6         31.2 

6       5             35.9 

2 

5       7 

60         34.0 

6     11             38.6 

15       21/2                 14       4 

12       51/2 

13       2 

2 

5       7 

66         36.8 

7      9             43.4 

2 

6       2 

5     0         31.4 

5       9             35.4 

14       7i/2                 13      9 

11     10  1/2 

12       7 

2 

6       2 

56         34.4 

66             39.9 

2 

6       2 

6     0         37.5 

6     11             42.7 

15       21/z                 14       4 

12       5% 

13       2 

2 

6       2 

6     6         40.6 

7      9             47.7 

2 

6       9 

50         34  .  3 

5      9             38.8 

15       3                     14       7 

12     11 

13       9 

2 

6       9 

5     6         37.7 

6       6            43  .  6 

2 

6       9 

60         41.1 

6     11             46.8 

16       31/2                 15       3 

13       9 

14     11 

2 

6       9 

6     6         44.5 

7       9             52.2 

2 

7       4 

50         44.6 

6     11              50.9 

16       31/2                 15       3 

13       9 

15      0 

2 

7       4 

5     6         48.4 

7      9             56  .  8 

2 

7      4 

6     6         48.4 

8       1             59.5 

16     10'/2                 15     10 

14       4 

15       7 

2 

7      4 

6     0         52.0 

3 

7     11 

66         48  .  2 

6     11             54.7 

17      41/2                 15     10 

14       0 

15       6 

3 

7     11 

6     0         52.2 

7      9            61.3 

3 

7     11 

66         52.2 

8       1             64.0 

17     Iiy2                 16       6 

14       7 

16       2 

3 

7     11 

70         56.1 

3 

8       6 

6     6         51.7 

.6     11             58.6 

17       5                     15     10 

14       01/2 

15       6 

3 

8       6 

6     0         56.0 

7       9             65  .  6 

3 

8       6 

6     6         56.0 

8       1             68.6 

18       0                     16       6 

14       71/2 

16       2 

3 

8       6 

7     0         60.2 

10 


NOTES  ON  POWER  PLANT  DESIGN 


HEINE  WATER-TUBE  BOILERS 


Tubes 

Steam  Outlet 

31/Z" 

Shells 

Height  of 

Square 

Diameter 

Height  of            Center  Line 

Horse- 

Feet. 
Heating 

Flange  Above        Above  Floor 
Floor                     Level 

power 

surface 

No.       Length 

No.         Diam.  Length 

Diam.                    Level                   Special 

Double- 

280 

2808 

171          16 

Ins.       Ft.    Ins. 
2             36         19     41/2 

Ins.                     Ft.  Ins.                    Ft.     Ins. 
8                        14       1                      11     111/2 

shell 

314 

3140 

171         18 

for            36         21     41/2 

for                     14       1                      11     111/2 

boilers 

328 

3280 

202         16 

all             36         19     41/2 

all                      14       8                      12       6i/2 

367 

3669 

202         18 

horse-      36         21     4V2 

horse-                  14      8                     12      6i/2 

297 

2978 

182         16 

powers     36         19     4% 

powers                 14       1                     11     '  1  V4 

333 

3330 

182         18 

36         21     41/2 

14       1                     11     lli/2 

348 

3479 

215         16 

36         19     4  1/2 

14      8                     12       61/z 

389 

3892 

215         18 

36         21     4i/2 

14       8                     12       6i£ 

254 

2546 

154         16 

36         19     4  Vi 

12     lOVi                10    101/2 

285 

2848 

154         18 

36         21     41/2 

12     10  1/2                 10     IQi/j 

Two 

284 

2840 

172         16 

42         19     61/2 

13      41/2                 11       4 

sections 

317 

3176 

172         18 

42         21     61/2 

13      41/2                 11       4 

over 

341 

3416 

210         16 

42         19     6i/2 

13       111/2                         11       11 

one 

-       382 

3822 

210         18 

42         21     61/2 

13     11  Vi                 11     11 

furnace. 

312 

3128 

190         16 

42          19     61/2 

13      4i/2                 11       4 

350 

3498 

190         18 

42         21     61/2 

13      41/2                 11       4 

576 

3766 

232         16 

42         19     6i/2 

13      111/2                       11       11 

421 

4212 

232         18 

42         21     61/2 

13      111/2                       11       11 

440 

4400 

274         16 

42         19     61/2 

14       61/2                 12       6 

492 

4924 

274         18 

42         21     6»/2 

14       61/2                 12       6 

343 

3432 

208         16 

48         19     91/4 

13     101/2                 11       91/2 

384 

3840 

208         18 

48         21     91/4 

13     lOVi                 11       9V2 

412 

4122 

254         16 

48         19     91/4 

U     10  1/2                 12       71/2 

461 

482 

4612 
4822 

254         18 
300         16 

48         21     91/4 
48         19     91/4 

14     10  1/2                  12       71/2 
15       51/2                  13       21/2 

539 
448 
501 

5396 
4488 
5016 

300         18 
276         16 
276         18 

48         21     91/4 
48         19     91/4* 
48         21     9V4 

15       51/2                  13       21/2 
14     101/2                  12       71/2 
14     10  1/2                  12       71/2 

524 

5242 

326         16 

48         19     91/4 

15       51/2                  13       21/2 

586 

5862 

326         18 

48         21     91/4 

15       5i/2                  13       21/2 

Grates 

Space  Occupied 

Diam. 
Feed- 
pipe 

Blowoff 
Cocks, 

iy2" 

Diam. 

Furnace 
Width 

Bituminous 
Coal 
Length      Area 

Anthracite 
Pea  Coal 
Length        Area 

Standard  Setting 
Height                Height 
over                      over 
Safety-Valve        Breeching 

Special  Setting, 
Height 
over 
Shell 

Low   Ceilings 
Height 
over 
Breeching 

at  Front 

Ins. 

21/2 

No. 
4 

Ft.     Ins. 
9         1 

Ft.  Ins.     Sq.  Ft. 
6       0         55  .  2 

Ft.  Ins.       Sq.  Ft. 
7         0         63.6 

Ft.       Ins.             Ft.     Ins. 
15        41/2             15        6 

Ft.     Ins. 
13           1 

Ft.     Ins. 
14         5 

for 

9         1 

66         59.8 

7       10         71.3 

21/2 

all 

9         1 

6       0         59.8 

8         3         74.5 

15       111/2             16         1 

13         8 

15         0 

2V2 
21/2 

horse- 
powers 

9         1    . 
9        8 

7       6         64.4 
6       0         58.8 

7         0        67.5 

15         41/2             15         6 

13         1 

14         6 

2V2 
21/2 

9        8 
9        8 

6       6        63.6 
6       0        63.6 

7       10        75.6 
8         2         79.0 

15       lli/2              16         1 

13        8 

15         1 

9        8 

7       6        68.5 

2-11/2 

10        7 

5      0        53  .  7 

5        6         57.7 

13       111/2              13       10 

11       11 

12       11 

10        7 

5       6         59  .  0 

6         2         64  .  8 

2-11/2 

11         9 

5       0         59  .  7 

5         6         64.5 

14         7V2              14      .   3 

12         41/2 

13         3 

2-li/z 
2-11/2 

11         9 
11         9 

5       6         65.6 
6       0         71.5 

6         2         72.0 
6         7         77  .  3 

15         21/2              14       10 

12       11  >/2 

13       10 

2-  1  1/2 

2-11/2 

11         9 
12       11 

6       6         77.3 
5       0         65  .  7 

7        5         86.7 
5         6         70.8 

14         71/2              14         3 

12         41/2 

13         9 

2-1  1/2 

2-11/z 

12       11 
12       11 

5       6         72  .  1 
6       0         78  .  6 

6         2         79  .  5 

6         7         85.4 

15       21/2                14       10 

12          111/2 

14         6 

2-iy2 
2-11/2 

12       11 
12       11 

6       6         85  .  0 
6       0         85.0 

7         5         95  .  7 
7         9       100.0 

15         91/2             15         5 

13         61/z 

15         1 

2-11/2 
2-2 

12       11 
14          1 

7       9         91.5 
5      0        71.5 

5         7         78.0 

15         3                  14         7 

12       11 

13         9 

2-2 
2-2 

14         1 
14         1 

5       6         78.5 
6       0        85.3 

6         2         87  .  2 
6         8         93.6 

16         31/2              15         9 

13        9 

14       11 

2-2 
2-2 

14         1 
14         1 

6       6         92.8 
6       0         92.3 

7         5       104.8 
7        9       109.5 

16       10  1/2             16         4 

14         4 

15         6 

2-2 
2-2 

14         1 
15         3 

76         99.7 
6       0         92.7 

6         8       101.8 

16         3V2              15         9 

13         9 

15         0 

2-2 
2-2 

15         3 
15         3 

6       6       100.3 
6       0       100.3 

7         6       114.0 
7       10       119.1 

16       101/2              16         4 

14         4 

15         7 

15         3 

7       6       108.0 

NOTES  ON  POWER  PLANT  DESIGN 


11 


STIRLING  BOILERS 

These  boilers  clean  from  the  side,  and  only  two  can  be  set  together  without  a  space  between. 
If  necessary  the  boiler  may  be  set  without  a  space  at  the  back,  but  it  is  advisable  to  have  at  least 
3  feet  back  of  the  rear  wall. 

These  boilers  are  also  built  with  attached  superheaters.  The  superheater  is  placed  at  differ- 
ent parts  of  the  setting,  according  to  the  number  of  degrees  of  superheating  desired. 

The  following  table  gives  dimensions  of  this  boiler  for  different  boiler  horse-powers. 

If  the  boiler  is  equipped  with  a  superheater,  deduct  10  per  cent  from  the  rated  horse-power. 
If,  however,  the  superheater  is  flooded  the  capacity  of  the  boiler  is  increased  approximately  7  per 
cent  above  the  ratings  given. 


HORSE-POWER   OF   STIRLING   BOILERS 


CLASS 


Width  of 
Setting 
Single 
ft.   in. 

Battery* 
feet 

B-low 
11'  11" 
14'  0" 

P 
15'4'/2" 

18'  7" 

E 

15'  3" 
16'  3" 

B 

15'  8" 
14'  0" 

A 

Height 
18'  9" 
Depth 
16'  0" 

Q 

18'  10" 
18'  9" 

F 
20'  7" 
16'  9" 

R 
20'  8" 
18'  2" 

K 

21'  10" 
17'  7" 

L 
22'  4" 
18'  3" 

N 
24'  6" 
18'  10" 

5    6 

10 

50 

50 

6    0 

11 

55 

'75 

60 

6    G 

12 

65 

90 

70 

7    0 

13 

75 

i\5 

100 

80 

iis 

145 

140 

145 

ino 

ies 

i75 

7    6 

14 

85 

130 

115 

90 

130 

165 

155 

160 

170 

185 

195 

8    0 

15 

95 

145 

125 

100 

145 

180 

175 

180 

185 

205 

220 

8    6 

16 

105 

160 

140 

110 

160 

200 

190 

200 

205 

230 

240 

9    0 

17 

115 

175 

150 

120 

175 

215 

205 

215 

225 

250 

260 

9    6 

18 

125 

190 

165 

130 

190 

235 

225 

235 

245 

270 

285 

10    0 

19 

135 

205 

175 

140 

205 

255 

240 

250 

260 

290 

305 

10    6 

20 

140 

220 

190 

150 

215 

270 

260 

270 

280 

310 

330 

11    0 

21 

150 

230 

200 

160 

230 

290 

275 

285 

300 

330 

350 

11    6 

22 

160 

245 

215 

170 

245 

310 

295 

305 

315 

350 

370 

12    0 

23 

170 

260 

225 

180 

260 

325 

310 

325 

335 

370 

395 

12    6 

24 

180 

275 

240 

190 

275 

345 

330 

340 

355 

395 

415 

13    0 

2.5 

190 

290 

250 

200 

290 

360 

345 

360 

375 

415 

435 

13    6 

26 

200 

305 

265 

210 

305 

380 

360 

375 

390 

435 

460 

14    0 

27 

210 

320 

275 

220 

320 

400 

380 

395 

410 

455 

480 

14    6 

28 

220 

335 

290 

230 

335 

415 

395 

410 

430 

475 

505 

15    0 

29 

230 

350 

300 

240 

350 

435 

415 

430 

450 

495 

525 

15    6 

30 

240 

365 

315 

250 

360 

450 

430 

450 

465 

515 

545 

16    0 

31 

250 

375 

330 

260 

375 

470 

450 

465 

485 

540 

570 

16    6 

32 

260 

390 

340 

270 

390 

490 

465 

485 

505 

560 

590 

17    0 

33 

265 

405 

355 

280 

405 

505 

485 

505 

520 

580 

610 

17    6 

34 

275 

420 

365 

290 

420 

525 

500 

520 

540 

600 

635 

18    0 

35 

285 

435 

380 

300 

435 

515 

515 

510 

560 

620 

655 

sides. 


*  The  horse-power  is  double  for  battery  width  shown.     Single  boilers  require  an  alley  on  one  side;  battery  boilers  require  an  alley  on  both 


12 


NOTES  ON  POWER  PLANT  DESIGN 


BABCOCK  AND  WILCOX  BOILERS 

These  boilers  clean  from  the  side.  There  must  be  a  space  of  at  least  5  feet  between  each 
set  of  two. 

The  tables  give  space  taken  up  by  boilers  with  vertical  headers.  For  inclined  headers,  any 
number' of  tubes  high,  add  3  feet  8  inches  to  the  length  given.  A  double-deck  boiler  is  10  inches 
higher  than  a  single-deck  boiler  of  same  number  of  tubes  high. 

Space  must  be  left  in  front  of  the  boiler  to  enable  the  lowest  tube  to  be  replaced. 

BABCOCK  AND  WILCOX  VERTICAL  HEADER  BOILERS. — Single  Deck 


Horse- 

power 

Heating 

Sections                                             Drums 

at  10 

surface. 

Steam 

Square 

Square 

Nozzle 

Opening 

Feet 

Feet 

Wide 

High  Long             No.         Dia.              Length 

Dia. 

Flange 

Dia.      Flange 

Ft.                               Ins.            Ft. 

Ins. 

Ins. 

Ins. 

Ins.       Ins. 

One 

101.8 

1018 

6 

9         16                  1              36              18 

7  Vi 

5 

11 

5         11 

Boiler 

114.3 

1143 

6 

9          18                  1             36             20 

2 

5 

11 

5         11 

in 

117.5 

1175 

7 

9         16                 1             36             18 

7'/4 

5 

11 

5         11 

One 

132.0 

1320 

7 

9         18                 1             36             20 

2 

5 

11 

5         11 

Battery. 

134.5 

1345 

8 

9          16                  1              42              18 

7«/4 

5 

11 

5         11 

151.0 

1510 

8 

9          18                  1             42             20 

2 

5 

11 

5          11 

150.2 

1502 

9 

9          16                  1             42              18 

71/4 

5 

11 

5         11 

168.7 

1687 

9 

9          18                  1              42             20 

2 

6 

121/2 

6         12i/2 

203  .  6 

2036 

12 

9          16                  2             36              18 

7Vi 

8 

15 

8         15 

228.7 

2287 

12 

9         18                2             36             20 

2 

5 

11 

8         15 

235.1 

2351 

14 

9         16                 2             36             18 

7% 

5 

11 

8         15 

264.0 

2640 

14 

9         18                2             36             20 

2 

5 

11 

8         15 

269.0 

2690 

16 

9          16                  2             42              18 

7V4 

5 

11 

8         15 

302.1 

3021 

16 

9          18                  2             42             20 

2 

5 

11 

8         15 

300.5 

3005 

18 

9         16                  2             42              18 

71/4 

5 

11 

8         15 

337.5 

3375 

18 

9         18                 2             42             20 

2 

5 

11 

8          15 

352.7 

3527 

21 

9          16                  3              36              18 

7V4 

5 

11 

10         171/2 

396.0 

3960 

21 

9          18                  3             36              20 

2 

5 

11 

10         171/2 

Mud-drums 

Height  from 

Front  of 

Grates 

Safety 

Floor  to 

Boiler  to 

Valve 

top  of 

Center  of 

Hand 

Blow-off 

Steam 

Steam 

No.         Dia. 

Feed 

Hole 

No.     Dia. 

Outlet 

Outlet 

Length 

Width 

Area 

Ins 

Ins. 

No. 

Ft.       Ins. 

Ft.     Ins. 

Ft.       Ins. 

Ft.       Ins. 

1             3V 

'•> 

[  Vi 

1 

1 

2 

14         8 

3         2 

6         0 

3         10 

23.00 

1              31/2 

[!/2 

1 

1 

2 

14         8 

or 

7         0 

3          10 

26.81 

1              3V 

1 

1 

2Vi 

14         8 

8         2 

6         0 

4           5 

26.50 

1             4 

I  Vi 

1 

1 

21/2 

14         8 

7         0 

4           5 

30.94 

1              4 

[  1/2 

2 

1 

15         2 

6         0 

5           0 

30.00 

1             4 

11/2 

2 

1 

21/2 

15         2 

7         0 

5           0 

35.00 

1             4 

11/2 

2 

1 

1J/2 

15         2 

6         0 

5           7 

33.50 

1             4V 

2 

11/2. 

2 

1 

15         2 

7         0 

5           7 

39.06 

2             31/2 

2  " 

3 

2 

21/2 

15         8 

6         0 

7           4 

44.00 

2             3V 

2 

2 

3 

2 

2V2 

15         8 

7         0 

7           4 

51.31 

2             4 

2 

4 

2 

2V2 

15         8 

6         0 

8           6 

51.00 

2             4 

2 

4 

2 

2V2 

15         8 

7         0 

8           6 

59.50 

2             4 

2 

4 

2 

2V2 

16         2 

6         0 

9           8 

58.00 

2             4 

2 

4 

2 

2V2 

16         2 

7         0 

9           8 

67.66 

2             4 

2 

4 

2 

21/2 

16         2 

6         0 

10         10 

65.00 

4J/2 

2 

4 

2 

2V2 

16        41/2 

7         0 

10         10 

75.81 

3             4 

21/2 

4 

3 

2V2 

15        9 

6         0 

12           7 

75.50 

3             4 

21/3 

4 

3 

2i/2 

15        9 

7         0 

12           7 

88.06 

Space  Occupied 

Approx. 

Approx. 

Approx. 
Weight 

Suspended 
Weight 

Total 
Weight 

Approx. 

of 

Including 

of 

Shipping 

Length 

Width 

Water 

Water 

Setting 

Weight 

Red  Brick 

Fire-brick 

Ft.         Ins. 

Ft.       Ins. 

No. 

No. 

17         91/2 

6 

8 

< 

),200 

29  ,300 

120  ,000 

26  ,000 

14,200 

3250 

19        9 

6 

8 

1( 

),170 

31  ,300 

130  ,600 

27  ,500 

15  ,600 

3550 

17        9i/2 

7 

3 

10  ,020 

32,100 

126  ,000 

28  ,600 

14  ,500 

3450 

19        9 

7 

3 

1 

,080 

34  ,300 

137  ,800 

30  ,300 

16  ,000 

3700 

17        9i/2 

7 

10 

12,330 

38  ,600 

135  ,300 

32,700 

15,100 

3700 

19        9 

7 

10 

K 

,720 

41  ,300 

147  ,000 

34  ,800 

16  ,600 

3950 

17        9i/2 

8 

5 

13,220 

41  ,300 

142  ,800 

36  ,400 

15  ,300 

3950 

19        9 

8 

5 

14 

1,670 

44  ,200 

155,100 

38  ,300 

16  ,700 

4100 

17        91/2 

10 

2 

18,400 

59  ,200 

151  ,500 

47,400 

15  ,800 

4000 

19        9 

10 

2 

2( 

),340 

63  ,200 

163  ,600 

50  ,300 

17  ,400 

4550 

17        91/2 

11 

4 

20,040 

64  ,900 

162  ,500 

53  ,600 

16  ,400 

4400 

19        9 

11 

4 

2J 

!.160 

69  ,300 

175,100 

56  ,000 

17  ,900 

4700 

17        91/2 

12 

6 

24  ,600 

78  ,000 

178  ,900 

62  ,200 

17  ,200 

4700 

19        9 

12 

6 

2" 

r,440 

83  ,400 

191  ,900' 

65  ,900 

18  ,900 

5200 

17        91/2 

13 

8 

26  ,440 

83  ,600 

190  ,700 

68  ,400 

17  ,800 

4950 

19        9 

13 

8 

2< 

),340 

89  ,300 

204  ,900 

72  ,500 

19  ,500 

5300 

17        9i/2 

15 

5 

30  ,OCO 

108  ,700 

209  ,800 

79,100 

18,100 

5200 

19         9 

15 

5 

33  ,240 

116,200       ' 

224,100 

83  ,900 

20  .000 

5400 

NOTES  ON  POWER  PLANT  DESIGN 


13 


BABCOCK  AND  WILCOX  VERTICAL  HEADER  BOILERS. — Single  Deck 


Horse-power 
at  10 
Sq.  Feet 

Heating- 
surface 
Sq.  Ft. 

Width  of 
Settings 
Ft.        Ins. 

Shipping 
Weight 

Red  Brick 

Number 

Fire  Brick 
Number 

Two 

203.6 

2036 

11        11 

52,000 

20,300 

6,500 

228.6 

2286 

11        11 

55,000 

22,000 

7,100 

Boilers 

285.0 

2350 

13          1 

57,200 

20,900 

6,900 

in  One 

264.0 

2640 

13          1 

60,600 

23,000 

7,400 

Battery. 

269.0 

2690 

14          3 

65,400 

21,900 

7,400 

302.0 

3020 

14          3 

69,600 

24,000 

7,900 

300.4 

3004 

15          5 

72,800 

22,200 

7,700 

337.4 

3374 

15          5 

76,600 

24,300 

8,200 

407.2 

4072 

19          6 

94,800 

26,800 

8,000 

457.4 

4574 

19          6 

100,600 

29,400 

9,100. 

470.2 

4702 

21         10 

107  ,200 

27,900 

8,800 

528.0 

5280 

21         10 

112,000 

30  ,500 

9,400 

538.0 

5380 

24          2 

124  ,400 

30,200 

9,400 

604.2 

6042                     24          2 

131  ,800 

32,400 

10,400 

601.0 

6010                     26          6 

136  ,800 

31,600 

9,900 

675.0 

6750                    26          6 

145,000 

33,600 

10,600 

705.4 

7054                     30          0 

158  ,200 

31  ,650 

10,400 

792.0 

7920                     :J()          0 

167  ,800 

34  ,750 

10,800 

Both  the  B.  &  W.  and  the  Stirling  have  cleaning  doors  for  blowing  soot  from  the  tubes  on  the 
side,  consequently  only  two  boilers  can  be  placed  side  by  side  without  an  aisle. 

The  height  of  the  tubes  above  the  grate  can  be  made  to  suit  the  requirements  of  the  engineer; 
a  much  greater  height  is  used  now  than  was  the  custom  a  few  years  ago. 

In  many  boiler  houses  the  boilers  are  located  on  the  first  floor  above  the  basement  which 
may  be  at  ground  level  or  below  ground  level. 

The  space  below  the  boiler  is  used  for  collecting  the  ash,  for  the  main  steam  line  and  feed 
pump  lines,  for  conveying  machinery,  etc.  The  boilers  are  supported,  in  such  cases,  by  steel  beams 
running  between  the  columns  which  must  be  spaced  to  suit  the  width  of  the  boilers  used. 

The  column  spacing  is  often  made  unequal  to  allow  for  a  5  or  6  ft.  aisle  between  batteries. 

In  some  cases  where  small  units  are  installed,  the  two  boilers  in  any  one  battery  are  carried 
at  the  front  end  by  steel  beams,  running  from  the  face  of  a  column  at  one  side  of  the  battery  to 
a  similar  column  at  the  other  side.  This  method  of  supporting  requires  a  rather  heavy  beam. 
More  often  there  is  a  column  in  the  center  of  the  battery.  In  every  case  the  columns  must  be 
protected  by  a  sleeve  so  that  should  the  brickwork  of  the  boiler  become  burned  through,  there 
would  be  no  possibility  of  the  heat  of  the  fire  softening  the  column. 

This  sleeve  is  frequently  made  of  thin  iron  encircling  the  column  to  a  height  of  three'  or  four 
feet  above  the  tubes,  the  sleeve  being  open  at  the  bottom  and  at  the  top  to  allow  of  a  circulation 
of  air  between  the  sleeve  and  the  column. 

When  boilers  are  carried  by  beams  attached  to  the  side  of  the  columns  there  is  an  eccentric 
load  brought  to  the  end  columns.  These  columns  adjacent  to  the  aisles  between  batteries  must 
be  diagonally  braced  above  the  boilers  on  account  of  this  eccentric  loading.  The  back  ends  of 
the  boilers  may  be  supported  in  the  same  way  as  the  front  ends  or  I  beam  uprights  resting  on  steel 
floor  beams,  may  serve  to  carry  the  cross  beams  from  which  the  drums  of  the  boiler  are  suspended. 

When  a  boiler  house  is  arranged  with  a  double  row  of  boilers,  having  a  firing  aisle  in  the  centre 
the  coal  pocket  is  often  suspended  from  the  columns  so  as  to  utilize  the  space  over  the  firing  aisle. 

Economizers  if  used,  would  then  be  located  over  the  boilers  at  the  back  end ;  this  plan  utilizes 
space  otherwise  wasted  but  makes  a  boiler  room  which  is  dark.  An  arrangement  found  in  some 
of  the  large  plants  in  Chicago  secures  both  a  well  lighted  and  a  well  ventilated  boiler  room. 


14 


NOTES  ON   POWER  PLANT    DESIGN 


The  boilers  at  both  front  and  back  are  supported  by  columns  which  are  carried  up  to  the  roof. 
A  coai  pocket  is  hung  between  these  columns  over  each  row  of  boilers  and  the  middle  bay,  which 
is  the  firing  aisle,  is  open  to  the  roof,  which  in  this  bay  is  of  the  monitor  type. 

FLUES  FOR  BOILERS 

• 

The  area  of  the  flue  leading  from  a  row  of  boilers  to  the  stack  should  be  as  great  as  the  area 
of  the  stack  designed  to  carry  the  row.  It  is  evident  that  a  greater  draft  obtained  from  a  high 
stack  would  diminish  the  cross  sectional  area  required  by  a  shorter  stack  giving  less  draft.  The 
old  rule  which  applied  to  hand  fired  boilers  by  which  the  flue  area  was  made  from  1/8  to  1/10  the 
grate  area  does  not  hold  with  stoker  fired  boilers  under  which  coal  is  burned  at  three  times  the 
rate  found  common  with  hand  fired  boilers. 

To  illustrate  the  method  of  determining  the  size  of  the  flue  for  a  row  of  boilers  let  us  assume 
that  5000  Ibs.  of  coal  are  burned  per  hour  under  a  battery  of  boilers.  Chimney  150  feet  high. 
Referring  to  the  chart  of  chimney  capacity  in  the  section  treating  of  chimneys,  it  is  seen  that  a 
chimney  150  feet  tall  will  take  care  of  176  Ibs.  of  coal  per  hour  per  sq.  ft.  of  chimney  area  accord- 
ing to  Kent's  values  and  157  Ibs.  according  to  Christie's  values. 

It  appears  from  these  figures  that  a  flue  of  from  28  to  32  sq.  ft.  area  is  required. 

BOILERS   USING   FUEL  OIL 

In  the  middle  western  states  and  in  the  southwestern  part  of  the  country  oil  is  in  general 
use  for  steam  generation. 

On  account  of  the  sudden  fluctuations  in  the  price  of  oil  here  in  the  east  very  few  concerns 
in  this  part  of  the  country  have  used  oil. 

Contracts  are  now  being  made,  however,  for  delivery  of  oil  at  a  fixed  price  through  a  long 
period  of  years  and  there  is  every  reason  to  believe  that  the  use  of  oil  in  this  part  of  the  country 
will  increase. 

Texas  oil  has  a  heating  value  of  approximately  18,500  B.  T.  U.  per  pound.  It  contains  gen- 
erally about  2  per  cent  of  moisture  although  in  some  cases  as  much  as  25  per  cent  has  been  found. 

The  gross  efficiency  of  an  oil  fired  boiler  plant  is  with  good  management  about  82  per  cent; 
as  2  per  cent  of  the  steam  made  is  used  in  heating  the  oil  and  in  spraying  it,  a  net  efficiency  of  80 
per  cent  may  be  expected. 

An  efficiency  of  75  per  cent  would  be  considered  very  good  for  a  coal  fired  boiler,  70  being 
nearer  that  obtained  in  every  day  running  in  the  best  plants. 

The  price  of  oil.  varies  either  side  of  $1.00  per  barrel  of  42  gallons,  8  Ibs.  to  the  gallon. 

A  table  giving  the  number  of  barrels  of  oil  equivalent  to  a  ton  of  coal  burned  with  boiler  effi- 
ciencies varying  from  65  to  75  per  cent  will  enable  one  to  make  a  comparison  of  the  cost  of  evapora- 
tion, using  oil  at  so  much  a  barrel  as  against  coal  of  a  certain  price  per  ton. 

Heat  Value  of  Coal  14,600  per  Ib. 


Equivalent  Evaportation  per  Ib.  coal  from  and  at 
212°  F.  in  Ibs 

Barrels  of  oil  336  Ibs.  to  barrel  18,500  B.  T.  U.  per 
Ib.  burned  with  80  per  cent  net  efficiency  equiv- 
alent to  one  ton  of  coal  of  14,600  B.  T.  U.  to  Ib. 


Boiler  Efficiency 

.750 

.725 

.70 

.675 

.650 

11.284 

10.908 

10.532 

10.392 

9.779 

5.543 

4.257 

4.110 

3.964 

3.817 

Oil  weighs  8  Ibs.  per  gallon. 
42  gallons  per  barrel. 

The  crude  oil  has  to  be  stored  in  steel  tanks,  generally  placed  underground  outside  of  the 
building.     The  oil  in  the  tank  must  be  heated  by  a  steam  coil  in  order  to  keep  it  sufficiently  fluid 


NOTES  ON  POWER  PLANT  DESIGN  15 

to  flow  through  the  suction  pipe  of  the  oil  pump  supplying  the  burners  with  oil  under  30  to  50  Ibs. 
pressure.  The  exhaust  of  the  oil  pump  is  frequently  used  to  still  further  heat  the  oil  before  it  enters 
the  burner. 

The  temperature  of  the  oil  should  not  be  high  enough  to  cause  the  gas  to  volatilize  as  this 
would  cause  the  flame  at  the  burner  to  be  extinguished  and  might  result  in  a  flooding  of  the  furnace 
and  an  explosion. 

The  advantages  and  the  disadvantages  of  petroleum  as  a  fuel  compared  with  coal  are  given 
in  "Steam"  thirty-fifth  edition,  Babcock  and  Wilcox  Co.'s  catalogue,  page  214,  as  follows: 

The  advantages  of  the  use  of  oil  fuel  over  coal  may  be  summarized  as  follows : 

1st.  The  cost  of  handling  is  much  lower,  the  oil  being  fed  by  simple  mechanical  means,  result- 
ing in: 

2nd.  A  general  labor  saving  throughout  the  plant  in  the  elimination  of  stokers,  coal  passers, 
ash  handlers,  etc. 

3rd.  For  equal  heat  value,  oil  occupies  very  much  less  space  than  coal.  This  storage  space 
may  be  at  a  distance  from  the  boiler  without  detriment. 

4th.  Higher  efficiencies  and  capacities  are  obtainable  with  oil  than  with  coal.  The  combus- 
tion is  more  perfect  as  the  excess  air  is  reduced  to  a  minimum;  the  furnace  temperature  may  be 
kept  practically  constant  as  the  furnace  doors  need  not  be  opened  for  cleaning  or  working  fires; 
smoke  may  be  eliminated  with  the  consequent  increased  cleanliness  of  the  heating  surfaces. 

5th.  The  intensity  of  the  fire  can  be  almost  instantaneously  regulated  to  meet  load  fluctua- 
tions. 

6th.  Oil  when  stored  does  not  lose  in  calorific  value  as  does  coal,  nor  are  there  any  difficulties 
arising  from  disintegration,  such  as  may  be  found  when  coal  is  stored. 

7th.  Cleanliness  and  freedom  from  dust  and  ashes  in  the  boiler  room  with  a  consequent  sav- 
ing in  wear  and  tear  on  machinery;  little  or  no  damage  to  surrounding  property  due  to  such  dust. 

The  disdavantages  of  oil  are : 

1st.  The  necessity  that  the  oil  have  a  reasonably  high  flash  point  to  minimize  the  danger  of 
explosions. 

2nd.  City  or  Town  ordinances  may  impose  burdensome  conditions  relative  to  location  and 
isolation  of  storage  tanks,  which  in  the  case  of  a  plant  situated  in  a  congested  portion  of  the  city, 
might  make  the  use  of  this  fuel  prohibitive. 

3rd.  Unless  the  boilers  and  furnaces  are  especially  adapted  for  the  use  of  this  fuel,  the  boiler 
upkeep  cost  will  be  higher  than  if  coal  were  used.  This  objection  can  be  entirely  obviated,  how- 
ever, if  the  installation  is  entrusted  to  those  who  have  had  experience  in  the  work,  and  the  opera- 
tion of  a  properly  designed  plant  is  placed  in  the  hands  of  intelligent  labor. 

SIZE  OF  STACK  REQUIRED   FOR  OIL  BURNING  BOILERS 

The  cross  sectional  area  of  stack  for  an  oil  burning  boiler  need  be  only  60  per  cent  of  that 
required  by  the  same  plant  burning  coal.  This  may  be  shown  by  a  simple  calculation. 

The  composition  of  a  semi-bituminous  coal  is  approximately  C  =  .85  H  =  .06  ash,  sulphur 
moisture,  etc.  .09. 

Fuel  oil  is  made  up  of  C  =  .84,  H  =  .12,  S.  N.  O.  and  moisture  .06. 

The  air  for  coal  =  11.5  X  .85  +  .06  x  34.5  =  12.34  Ibs.;  allowing  50  per  cent  dilution  in  order 
to  get  air  to  all  parts  of  furnace  gives  18.51  Ibs. 

For  oil  11.5  x  .85  +  .12  x  34.5  =  13.86;  allowing  20  per  cent  for  dilution  gives  16.63  Ibs. 

As  the  heat  utilized  by  the  boiler  from  a  pound  of  coal  is  about  10,000  B.  T.  U.,  while  that 
taken  up  from  a  pound  of  oil  is  about  14,800  B.  T.  U.,  it  is  evident  that  1.48  Ibs.  of  coal  would  be 
required  to  furnish  the  heat  absorbed  from  one  pound  of  oil  and  consequently  the  weight  of  gases 
from  the  coal  fired  boiler  would  in  comparison  with  the  oil  be  as  1.48  x  18.51  =  27.39  is  to  16.63, 
which  means  that  the  same  stack  will  with  oil  fired  boilers  have  1.65  the  capacity  of  coal  fired 
boilers. 

Many  plants  which  are  overloaded,  which  have  insufficient  chimney  area  and  in  which  there 
is  not  room  for  the  installation  of  mechanical  stokers  with  forced  or  induced  draft  fans,  have  adopted 
oil  burning. 


16  NOTES  ON  POWER  PLANT  DESIGN 


ECONOMIZERS 


Economizers  are  made  up  of  cast  iron  tubes  4"  to  4}/£"  inside  diameter  and  9'  long.  The  tubes 
are  turned  at  the  end  to  a  slight  taper  and  are  forced  into  top  and  bottom  headers  by  hydraulic 
pressure.  These  headers  are  made  to  take  different  numbers  of  tubes,  as  is  shown  by  the  table 
of  dimensions  given  on  page's  which  follow.  The  lower  headers  project  through  the  brick 
work  housing  and  are  joined  together  by  a  "bottom  branch  pipe"  running  lengthwise  of  the  econo- 
mizer. This  "bottom  branch  pipe"  has  on  one  side,  a  series  of  flanges  for  making  the  connection 
with  the  bottom  headers  and  on  the  opposite  side,  in  line  with  each  header,  a  hand  hole  through 
which  the  header  may  be  cleaned.  The  feed  water  enters  this  "bottom  branch  pipe"  at  the  end 
of  the  economizer  nearer  the  chimney  and  leaves  the  economizer  at  the  top,  at  the  end  nearer 
the  boiler.  The  top  headers  are  similarly  connected.  This  pipe  joining  the  top  headers  is  placed 
above,  instead  of  at  the  end  of  the  header,  and  at  the  opposite  side  of  the  economizer.  In  some 
cases  means  are  provided  for  washing  out  the  bottom  headers,  by  sending  a  stream  of  water  from 
a  hose  down  through  the  tubes  at  the  back  end  of  the  bottom  headers  and  letting  it  flow  along  the 
entire  length  of  the  bottom  headers  and  out  through  the  clean-out  openings  directly  opposite  the 
headers. 

In  setting  up  an  economizer,  room  should  be  left  opposite  these  clean-out  openings  so  that  a 
scraper  can  be  put  into  each  header  to  remove  any  scale  which  may  lodge  there,  as  the  headers 
are  sometimes  cleaned  out  in  this  way  instead  of  by  washing  out. 

In  order  to  repair  a  tube  and  replace  it  by  a  second  tube  without  dismantling  that  section  or 
that  header,  a  slot  is  made  in  the  upper  end  of  the  tube  with  a  chisel  so  as  to  enable  the  tube  to 
be  sprung  together.  The  tube  is  then  withdrawn  from  the  bottom  header  in  the  following  manner  : 

A  piece  of  iron  shaped  as  shown  by  the  accompanying  sketch  is  pushed  down  inside  the  tube 
and  moved  to  one  side  so  as  to  engage  the  bottom  end  of  the  tube,  this  piece  being  held  by  a  rod 
with  thread  and  nut  at  the  top.  A  second  piece  like  a  wedge,  is  held  against  the  first  piece  by  a 
second  rod  and  prevents  any  side  motion  of  the  first  piece.  By  screwing  on  the  first  nut  the  tube 
may  now  be  withdrawn  from  the  bottom  header.  The  new  tube  is  now  inserted,  driven  into  the 
bottom  header,  and  a  conical  wedge  used  to  make  the  joint  between  the  tube  and  the  top  header. 
Sometimes  a  tube  which  has  given  trouble  may  be  plugged  and  cut  out  of  service. 

As  the  tubes  are  withdrawn  through  the  top  of  the  economizer,  or  in  case  of  serious  mishap, 
the  entire  section  is  taken  up  through  the  top  of  the  economizer,  —  there  should  be  sufficient  room 
left  over  the  economizer  to  allow  for  this.  The  arrangement  of  the  brickwork  should  be  such  as 
to  enable  a  section  to  be  withdrawn  without  making  it  necessary  to  take  down  a  large  amount 
of  masonry. 

The  heating  surface  needed  may  be  put  either  in  one  large  economizer,  through  which  all  the 
gases  from  all  of  the  boilers  pass,  or  there  may  be  a  number  of  smaller  economizers  known  as  "unit 
economizers,"  one  for  each  battery  of  boilers.  With  the  first  arrangement,  any  accident  to  the 
economizer  which  might  put  it  out  of  service,  would  reduce  the  power  of  the  boiler  plant  10  or 
15  per  cent.  The  draft  would  be  reduced  to  a  considerable  amount  by  this  arrangement. 

In  the  second  arrangement,  as  only  one  unit  would  be  cut  out,  in  case  of  accident,  the  reduction 
in  power  of  the  boiler  plant  would  be  inappreciable. 

The  flue  gas  leaving  the  boiler  should  have  a  direct  passage  to  the  chimney  around  the  econo- 
mizer. Suitable  dampers  should  be  provided  so  that  the  gases  may  be  sent  either  through  the 
economizer  or  directly  to  the  chimney.  When  the  economizer  is  out  of  service  both  dampers  at 
entrance  and  exit  to  the  economizer  should  be  closed. 

In  general,  an  economizer  will  save  from  8  to  15  per  cent.  In  figuring  whether  the  saving  is 
going  to  pay  for  the  interest  on  the  first  cost,  and  for  the  depreciation,  the  saving  to  be  made  in 
any  particular  case  has  to  be  taken  into  account.  The  life  of  an  economizer  is  generally  considered 
to  be  20  years,  and  the  cost  set  is  generally  taken  as  about  $4.50  per  boiler  horse  power  or  $10  to 
$12  per  tube  erected.  This  latter  figure  does  not  include  an  induced  draft-outfit  which  if  installed 
would  add  to  the  cost. 

Reducing  the  temperature  of  the  flue  gas  by  passing  it  through  the  economizer  reduces  the 
draft  practically  in  the  proportion  that  the  absolute  temperature  of  the  flue  gas  is  reduced.  The 


NOTES  ON   POWER  PLANT  DESIGN 


17 


draft  is  still  further  reduced  by  the  friction  of  the  gas  in  passing  through  the  economizer  and  in 
the  many  instances  where  the  draft  is  poor,  it  would  be  unwise  to  install  an  economizer  unless 
an  induced  draft  fan  were  to  be  installed  also.  Usually  on  the  side  of  the  economizer  there  is  a 
space  about  12  inches  wide  left  between  the  last  tubes  and  the  casing  or  brickwork,  to  allow  of 
inspection.  Sometimes  there  are  two  such  passages,  one  either  side  of  the  economizer.  These 
passages  are  closed  by  side  dampers  when  the  economizer  is  in  use. 

Provision  should  be  made  for  removing  the  soot  from  the  bottom  of  the  economizer.  To 
remove  the  soot  which  collects  on  the  tubes,  scrapers  are  provided,  these  scrapers  being  in  the 
form  of  loose  collars  which  are  alternately  raised  and  lowered  by  chains  operated  from  a  shaft  run- 
ning along  the  top  of  the  economizer.  If  the  economizer  is  only  eight  tubes  wide,  one  shaft  will 
serve,  but  if  the  economizer  is  ten  or  twelve  tubes  wide  there  should  be  two  sets  of  stmfts.  In  place 
of  the  brickwork  walls  a  sectional  covering  of  steel  bolted  together  through  angle  irons  may  be 
used.  This  covering  is  insulated  by  building  it  up  of  two  steel  plates  with  2"  of  magnesia  or  asbes- 
tos as  an  insulating  material  between. 

The  economizers  must  each  be  provided  with  a  relief  valve  of  sufficient  size,  and  with  a  blow- 
off  valve.  Various  arrangements  of  economizers  as  applied  to  different  types  of  boilers,  and  the 
various  arrangements  of  the  direct  flues  may  best  be  seen  by  studying  some  of  the  cuts  of  power 
stations  or  by  referring  to  some  of  the  cuts  shown  on  later  pages. 

The  economizer  is  always  connected  on  the  feed  line  in  such  a  way  that  the  feed  may  be  by- 
passed around  the  economizer,  and  when  the  economizer  becomes  steam  bound  it  should  be  cut 
out  and  allowed  to  cool  until  the  steam  has  condensed. 


The  rise  of  temperature  of  the  feed-water  in  an  economizer  may  be  calculated  as  follows : 
Th  =  temperature  of  flue  gas  entering  economizer. 
Tc  =  temperature  of  flue  gas  leaving  economizer. 
th  =  temperature  of  feed  water  leaving  economizer. 


18  NOTES  ON  POWER  PLANT  DESIGN 

tc  =  temperature  of  feed  water  entering  economizer. 
.24  =  specific  heat  of  flue  gas. 

30  =  number  of  pounds  of  water  fed  per  boiler  H.  P. 
24  =  pounds  of  flue  gas  per  pound  of  coal. 

9  =  probable  evaporation  of  water  per  pound  of  coal. 
• 

QA 

(Tk  -  Te)  X  24  X  y  X  .24  =  30  (th  -  tc) 

Tc=Th-  1.562  (tk  -  tc) 

For  different  evaporations  or  for  different  weights  of  flue  gas  per  pound  of  coal  the  value  to 
replace  1.562  may  be  easily  figured. 

S  =  square  feet  of  heating  surface  in  the  economizer  per  boiler  H.  P.  or  per  30  Ibs.  of  feed 
water  fed  per  hour. 

3  =  B.T.U.  transmitted  per  square  foot  of  surface  per  hour  per  degree  difference  of  tempera- 
ture between  the  gases  outside  the  tubes  and  the  water  inside  the  tubes.  As  the  coldest  gas  is 
at  that  end  of  the  economizer  at  which  the  cold  water  enters  and  the  hottest  gas  at  the  end  where 
the  water  is  hottest,  there  can  be  but  little  error  in  taking  the  difference  of  the  mean  tempera- 
tures of  the  .gas  and  of  the  water. 


/.  .  \          1  *  n~r  *  c  th  -\~  tc\         o          e 

(lh  -  tc)  =  I ^ 2~ ) 

_  20tc  +  2  S  Th  +  .562  S  tc 
20  +  2.562  S 

The  Green  Economizer  Company  use  the  following  formula: 

S  (Th  -tc) 


th  -  tc  = 


(5  w  +  GC)  S 
2  GC 


In  this  w  =  pounds  of  feed  water  per  boiler  H.  P. 

G  =  pounds  of  flue  gas  per  pound  of  combustible. 
C  =  pounds  of  coal  per  boiler  H.  P.  hour. 

This  formula  is  practically  the  same  as  the  one  already  worked  out. 

EXAMPLE 

Flue  gas  leaves  the  boiler  and  enters  the  economizer  at  550°F.  The  feed  water  after  passing 
through  both  a  primary  and  a  secondary  heater  enters  the  economizer  at  200°  F.  What  is  the  tem- 
perature of  the  feed  water  leaving  the  economizer? 

What  is  the  temperature  of  the  flue  gases  leaving  the  economizer? 

It  is  customary  to  provide  from  3.5  to  5  sq.  ft.  of  heating  surface  in  an  economizer  per  boiler 
H.  P.  Assume  in  this  case  4  sq.  ft. 

_20  x  200  +  2  x  550  x  4  +  .562  x  4  x  200 

20  +  2.562  x  4 
th  =  292° 
Tc  =  550  -  1.562  (292  -  200)  =  407° 

The  feed  water  is  heated  from  200°  to  292°  by  the  economizer.  Suppose  the  boiler  pressure  car- 
ried in  a  battery  of  boilers  to  have  been  164.8  Ibs.  ab.  with  100°  superheat,  then  the  heat  needed  to 
make  a  pound  of  water  at  200°  F.  into  superheated  steam  of  pressure  and  conditions  specified  is 
1252  -168=  1084  B.T.U. 


NOTES  ON  POWER  PLANT  DESIGN 


19 


The  economizer  saved  92  B.  T.  U.  per  Ib.  of  water  or 


92 
1084 


=  .0849  say  8%  per  cent.     On  a 


coal  consumption  of  592  tons  per  week  with  coal  at  $4.20  per  ton  a  saving  of  8^  per  cent  amounts 
in  the  course  of  a  year  to 

.085  X  592  x  52  x  $4.20  =  $10,989 

The  economizer  consisting  of  672  tubes  cost  at  $12.00  a  tube,  $8,064;  the  piping  etc.  brought 
the  cost  up  to  $10,000. 

There  should  be  charged  against  the  economizer  which  may  be  assumed  to  be  worn  out  in 
20  years,  a  certain  percentage  for  depreciation  (see  later  pages)  which  we  will  take  as  3.02  per  cent, 
interest  5  per  cent,  taxes  1.5  per  cent,  insurance  0.5  per  cent  and  repairs  2.5  per  cent  making  a 
total  of  12.52  per  cent. 

.1252  x  $10,000  =  $1,252 

The  saving  apparently  amounts  to  10,989  -  1,252  =  $9,737  per  year. 

If  an  induced  draft  had  to  be  maintained  there  should  be  charged  against  the  economizer  the 
cost  of  running  the  fan  and  the  interest,  depreciation,  etc.  on  the  cost  of  the  outfit. 

This  would  make  the  saving  less.  In  spite  of  the  fact  that  figures  show  a  decided  saving 
made  by  the  use  of  an  economizer  many  engineers  will  not  recommend  their  installation. 

Some  arrangements  of  economizers  follow: 

The  resistance  offered  to  the  flue  gases  by  an  economizer  amounts  to  from  .25"  to  30"  of  water. 
In  many  instances  on  account  of  this  loss  of  draft,  it  becomes  necessary  to  install  an  induced  draft 
fan. 

Illustrations  of  induced  fan  outfits  as  erected  in  two  manufacturing  plants  are  shown. 


20 


NOTES  ON  POWER  PLANT  DESIGN 


GENERAL  DIMENSIONS  OF  GREEN'S  IMPROVED  FUEL 

ECONOMIZERS 
Height  over  gearing,  13  ft.  5%  in.     Height  over  section,  10  ft.  2%  in. 


Numbej  of  Tubes 

Su 

"E 

3 

Z 

Number  of  Rows 

•si 

M  c 
C    O 

—  w 

Dimensions  Inside 
Walls 

Area  Between 
Tubes 

i! 

External 
Heating  Surface 

III 

&    a 

g     ^ 
j>3  fl 

o 

3          £ 
2^0. 

|s| 

&      0 

With  One 
Side 
Damper 

With  Two 
Side 
Dampers 

32 

4 

8 

4'-10" 

3'-4" 

4'-l" 

4'  10" 

16.6 

23.85 

31.10 

1984 

408 

48 

4 

12 

7'-  3" 

44 

14 

44 

44 

44 

44 

2976 

612 

64 

4 

16 

9'-  8" 

4  4 

" 

' 

4  4 

44 

4  4 

3968 

816 

80 

4 

20 

12'-  1" 

4960 

1020 

96 

4 

24 

14'—  6" 

44 

44 

4 

44 

4 

4 

5952 

1224 

112 

4 

28 

16'-11" 

44 

44 

4 

44 

4 

4 

6944 

1428 

128 

4 

32 

19'-  4" 

4 

44 

4 

44 

4 

4 

7936 

1632 

144 

4 

36 

21'-  9" 

4 

44 

4 

44 

4 

4 

8928 

1836 

160 

4 

40 

24'-  2" 

4 

44 

44 

44 

4 

4 

9920 

2040 

176 

4 

44 

26'-  7" 

4 

44 

" 

4  4 

4 

4 

10912 

2244 

192 
208 

4 

4 

48 
52 

29'-    0" 
31'-  5" 

4 

44 

44 

44 

4 

44 

11904 
12896 

2448 
2652 

48 

6 

8 

4'-10" 

4'-8" 

5'-5" 

6'-  2" 

21.85 

29.10 

36.35 

2976 

612 

72 

6 

12 

7'-  3" 

<4 

44 

44 

44    / 

44 

44 

4464 

918 

96 

6 

16 

9'-  8" 

44 

44 

4 

44 

44 

44 

5952 

1224 

120 

6 

20 

12'-  1" 

44 

44 

• 

4 

44 

44 

7440 

1530 

144 

6 

24 

14'-  6" 

" 

44 

1 

4 

4 

44 

8928 

1836 

168 

6 

28 

44 

44 

4 

4 

'» 

44 

10416 

2142 

192 

6 

32 

19'-  4" 

44 

44 

4 

4 

'4 

44 

11904 

2448 

216 

6 

36 

21'-  9" 

44 

4 

44 

4 

4 

4  ' 

13392 

2754 

240 

6 

40 

24'-  2" 

44 

4 

44 

4 

4 

41 

14880 

3060 

264 

6 

44 

26'-  7" 

44 

4 

4 

4 

4 

41 

16368 

3366 

288 

6 

48 

29'-  0" 

44 

4 

4 

•  4 

44 

44 

17856 

3672 

312 

6 

52 

31'-  5" 

44 

4 

4 

,4 

44 

44 

19344 

3978 

336 

6 

56 

33'-10" 

44 

4 

4 

4 

44 

44 

20832 

4284 

360 

6 

60 

36'-  3" 

41 

4 

4 

4 

4  4 

1  4 

22320 

4590 

96 

8 

12 

7'-  3" 

6'-0" 

6'  -9" 

7'-  6" 

27.00 

34.25 

41.5 

5952 

1224 

128 

8 

16 

9'-  8" 

44 

44 

44 

44 

44 

14 

7936 

1632 

160 

8 

20 

12'-  1" 

44 

44 

44 

44 

44 

4  4 

9920 

2040 

192 

8 

24 

14'-  6" 

4  4 

4  4 

11904 

2448 

224 

8 

28 

16'-11" 

44 

44 

44 

44 

44 

44 

13888 

2856 

256 

8 

32 

197-  4" 

44 

44 

44 

4 

44 

44 

15872 

3264 

288 

8 

36 

21'-  9" 

44 

44 

44 

4 

44 

44 

17856 

3672 

320 

8 

40 

24'-  2" 

44 

44 

44 

4 

44 

44 

19840 

4080 

352 

8 

44 

26'-  7" 

44 

44 

44 

4 

44 

44 

21824 

4488 

384 

8 

48 

29'-  0" 

44 

44 

44 

4 

14 

44 

23808 

4896 

416 

8 

52 

31'-  5" 

44 

44 

i  < 

4 

44 

44 

25792 

5304 

448 

8 

56 

33'-10" 

44 

44 

" 

4 

44 

44 

27776 

5712 

480 

8 

60 

36'-  3" 

44 

4  4 

44 

4 

44 

44 

29760 

6120 

160 

10 

16 

9-  8" 

7'-4" 

8'-l" 

8'-  10" 

32.25 

39.50 

46.75 

9920 

2040 

200 

10 

20 

12'-  1" 

44 

44 

4  4 

4  4 

4  4 

U  1 

12400 

2550 

240 
280 

10 
10 

24 

28 

14'-  6" 

M 

«< 

.. 

.. 

" 

.< 

14880 
17360 

3060 
3570 

320 

10 

32 

19'-  4" 

44 

44 

44 

44 

44 

44 

19840 

4080 

360 

10 

36 

21'-  9" 

44 

44 

4  4 

4  4 

4  4 

4  4 

22320 

4590 

400 

10 

40 

24'-  2" 

7'-4" 

8'-l" 

8'-10" 

32.25 

39.50 

46.75 

24800 

5100 

440 

10 

44 

26'-  7" 

11 

44 

44 

•4 

4t 

44 

27780 

5610 

480 

10 

48 

29'-  0" 

44 

44 

44 

44 

44 

44 

29780 

6120 

520 

10 

52 

31'-  5" 

44 

44 

44 

44 

44 

44 

32240 

6630 

560 

10 

56 

33'  10" 

44 

44 

44 

44 

44 

44 

34720 

7140 

600 

10 

60 

36'-  3" 

44 

44 

44 

44 

4 

44 

37200 

7650 

640 

10 

64 

38'-  8" 

44 

44 

44 

44 

4 

•4 

39680 

8160 

680 

10 

68 

41'-  1" 

14 

44 

44 

44 

4 

44 

42160 

8670 

720 

10 

72 

43'-  6" 

44 

44 

44 

<  i 

4 

44 

44640 

9180 

760 

10 

76 

45'-l  1" 

44 

44 

44 

44 

4 

44 

47120 

9690 

800 

10 

80 

48'-  4" 

44 

4  4 

4  ' 

44 

4 

44 

49600 

10200 

240 

12 

20 

12'-  1" 

8'-8" 

9'-6" 

10'  3" 

39.25 

44.75 

51.50 

14880 

3060 

288 

12 

24 

14'-  6" 

44  . 

44 

44 

4  4 

44 

44 

17856 

3672 

336 

12 

28 

1&-11" 

20832 

4284 

384 

12 

32 

19'-  4" 

44 

44 

44 

4  4 

i  <, 

44 

23808 

4896 

432 

12 

36 

21'-  9" 

26784 

5508 

480 

12 

40 

24'-  2" 

4  4 

29760 

6120 

528 

12 

44 

26'-  7" 

44 

44 

44 

44 

44 

44 

32736 

6732 

576 

12 

48 

29'-  0" 

44 

44 

44 

44 

44 

4 

35712 

7344 

624 

12 

52 

31'-  5" 

4« 

4 

4 

" 

44 

4 

38688 

7956 

672 

12 

56 

33'-10" 

44 

4 

4 

44 

44 

4 

41664 

8568 

720 

12 

60 

3&-  3" 

44 

4 

4 

44 

44 

4 

44640 

9180 

768 

12 

64 

38'-  8" 

44 

4 

i 

44 

44 

4 

47616 

9792 

816 

12 

68 

41'-  1" 

<  i 

i 

i 

<  t 

44 

4 

50592 

10404 

864 

12 

72 

43'-  6" 

1  1 

' 

4 

4  ' 

4 

' 

53568 

11016 

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Qi 
O) 
N 

O 
Z 

O 
u 


Q 
etc 
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Q 
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C/) 


GENERAL  DIMENSIONS. 

c 
-i 

< 

I 

•o 

c 

c' 

§  s 

Jl 

c 

- 

,.,...,.,.„ 

- 

4 

j:     4C 

^ 

* 

o 

f.  . 

i 

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CO 

a  ~ 

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txoo  01  o  «-  «  n  g;  gj'g,  5" 

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Q 
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GENERAL  DIMENSIONS. 

Q 
X 

< 

fe 

i: 
0 

s 

§  'i 

o 

s 

Section. 

X 

r 

•s  •-' 

.*H 

* 

CO 

f  ,,,,-.,,,, 

f  =  ..  -.  ,  -.  ,  ,  ,  ,  , 

S  3  ,  ,  3  .  ,  *  ^  .  *  * 

1 

-  

J  d 

t  r>«  cS  ci  to  ^> 

tUltiUl 

U!  to  lull 

1  1  1  111  '11'" 

<>c-l    tO    C>  —    tO    C7>  -    CO 

nuuuuu 

a"*2? 

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N    CO  t  ^^>O    f^CO 

ooooooooo 

fiCO    TO^O    riOO    TO 

O  OO   O   ci    to  00   O   fl   t 
co  to  r^co  o  Q  ci  co  t 

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to  ONOO  too  HOO^O 
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tO  CO   O    ci    to 

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t  co  N  O   O  r^o  f>  co  «  O 
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uissdij 

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f  i  O   O    too   ci  O   O    tco 

O   O    tco   flO  O    too   flO 

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M     M     M     M     l-l     M     M 

24  NOTES  ON  POWER  PLANT  DESIGN 


MECHANICAL  STOKERS 

There  is  no  question  about  the  desirability  of  mechanical  stokers  in  a  plant  of  1500  H.  P. 

While  there  may  not  be  any  saving  in  the  cost  of  labor  on  a  plant  of  1500  H.  P.  the  protec- 
tion against  labor  troubles  which  a  stoker  affords  warrants  its  use  on  a  plant  of  this  size. 

On  plants  of  larger  size  the  saving  in  labor,  together  with  the  increased  capacity  to  be  obtained 
from  the  boilers,  the  freedom  from  smoke  troubles,  the  insurance  against  labor  troubles  and  the 
ability  to  push  a  boiler  from  a  banked  condition  to  150  per  cent  rating  in  ten  minutes  make  stokers 
absolutely  necessary. 

The  stokers  may  be  divided  into  classes: 

(1)  The  Taylor  and  The  Riley  underfed  stokers,  both  similar  to  the  cut  following. 

(2)  The  Murphy  and  the  Roney,  inclined  grates. 

(3)  The  chain  grate,  like  Green,  Keystone,  and  the  Babcock  &  Wilcox. 

(4)  The  American;  The  Jones;  both  underfed  stokers  but  differing  from  the  Riley  and  the 
Taylor. 

There  are  others  not  mentioned,  the  ones  named  being  those  most  commonly  found. 

The  Taylor  and  the  Riley  are  both  capable  of  quick  forcing  and  can  be  crowded  harder  than 
the  Murphy  or  the  Roney.  All  four  of  these  are  best  suited  for  a  good  grade  of  soft  coal.  The 
chain  grate  works  best  on  a  poorer  grade  of  coal. 

The  American  and  The  Jones  are  better  suited  for  small  units  than  for  large  units. 

Stokers  cost  from  $6  to  $10  per  rated  H.  P.  of  the  boiler.  The  higher  figure  includes  the  cost 
of  the  fan  and  engine  required  by  certain  types  of  stoker. 

See  Steam  Boilers,  Peabody  and  Miller  for  more  detailed  discussion  of  stokers. 

The  life  of  a  stoker  is  from  6  to  8  years,  consequently  a  high  rate  for  depreciation  must  be 
charged  against  it. 


NOTES  ON  POWER  PLANT  DESIGN 


25 


Dumping  Lever 


Tuyeres 


Weight 


Dump  Plato  OuUe 


26 


NOTES  ON  POWER  PLANT  DESIGN 


CHIMNEYS,   FLUES  AND  DRAUGHTS 

The  draft  of  a  chimney  depends  upon  the  temperature  of  the  gases  entering  the  chimney, 
the  temperature  of  the  gases  leaving  the  chimney,  the  height  of  the  chimney  and  the  temperature 
of  the  outside  air. 

In  figuring  the  draft,  an  average  temperature  of  the  outside  air  may  be  taken  as  55°. 

As  the  draught  of  a  chimney  is  due  to  the  difference  in  weight  of  a  column  of  cold  air  of  the 
height  of  the  chimney  and  the  column  of  hot  gas  in  the  chimney,  in  order  to  figure  the  draft  it  is 
necessary  to  know  the  mean  temperature  inside  the  chimney. 

From  work  done  on  three  or  four  chinmeys  from  3'  dia.  100  ft.  tall  to  16'  dia.  250  ft.  tall,  the 
variation  in  temperature  throughout  the  height  of  a  stack  has  been  plotted  and  an  equation  of 
the  form  HTn  =  K  fitted  to  the  curve. 

H  =  height  in  feet  of  chimney  at  any  point  above  middle  of 

flue,  the  lower  value  of  H  being  3  ft. 
T  =  absolute  temperature  in  degrees  F. 
T\  =  absolute  temperature  of  gases  entering  chimney. 
JV=25        log  K=  75.4032 


HTt.il 


The  mean  absolute  temperature  is  equal  to 

area  crosshatched 
#2-3 


This  equals 


#2-3 

Example:  Assume  temp,  at  a  level  3  ft.  above  centre  of 
flue  as  1000°  ab.  Top  of  chimney  231  ft.  above  centre  of  flue. 
Find  mean  temperature  and  probable  draft  when  outside  air 
is  at  55°  F. 


1000x75      /231 


24 


24 
25 


-1 


231  -3 


=  873.0 


11.78  x  14.7      v  (14.7  -  .6  x  .04) 


491.5 


873 


v  =  20.96 


-  =  .0477 

v 


12.39  x  14.7 
491.5 


_0X_14_.7_ 
459.5  +  55 


v  =  12.97     —  =   .0771 

v 


(.0771  -  .0477)  (231  -  3)  x  12 
62.4 


=  1.29 


In  the  preceding  calculation,  the  pressure  in  the  chimney  was  needed,  this  was  assumed  to 
be  (14.7  -  .6  x  .04)  or  the  draft  was  assumed  to  be  1.20"  at  the  bottom  of  the  chimney. 

11.78  is  the  specific  volume  of  flue  gas., 
12.39  the  specific  volume  of  air. 


NOTES  ON  POWER  PLANT  DESIGN 


27 


The  draught  at  the  boiler  will  be  less  than  that  at  the  chimney  end  of  the  uptake  on  account 

t  inction  in  the  uptake,  bends,  etc.     Generally  .10"  loss  of  draught  is  allowed  for  each  100  ft  of 

Hue  and  .05    for  each  right  angle  bend.     In  addition  to  this  there  is  from  .25  to  .3"  lost  due  to 

resistance  offered  by  the  tubes  of  the  boiler.     In  addition  to  this  there  is  the  resistance  offered 

by  the  fuel  bed  and  the  grates. 


POUNDS  OF  COAL  BURNED  PER  SQUARE  FOOT  OF  ORATE  SURFACE  PER  HOUR. 
CORVES  SHOWING  DRAFT  REQUIRED  BETWEEN  FURNACE  AND  ASH-PIT  AT  DIFFERENT  COMBUSTION  RATES  FOR  VAR.OUS  KINDS  OF  COAk 


°if 
from  actual  1  tts 

The  accompanying  plot  taken  from  their  work  needs  no  explanation. 


the  loss  of  draft  betwee*  t^  furnace  and  the  ash  pit,  for  dif- 
*"  ^  determined  by  the  StirlinS  Boiler  Company 


K    i    dv!aft  -needed  at,base  °f  Stack  by  a  boiler  20°  feet  from  chimney  with  2  sharp 
foot  of  grate    er  hour"       nmg  mn      ""^  bituminous  coal  at  a  rate  of  25  lbs-  of  c°al  per  square 

Loss  of  draft  between  furnace  and  ash  pit  (plot)  =    13" 

200  ft.  flue  loss      ......      .     .  -  .20" 

2  sharp  bends  loss       .....  =  JO" 

Loss  due  to  tubes  and  passages  in  boiler          .  =  .30" 


.73" 


28 


NOTES  ON  POWER  PLANT  DESIGN 


EXAMPLE:  A  boiler  plant  has  a  chain  grate  burning  30  pounds  of  bituminous  slack  coal  per 
square  foot  of  grate  per  hour,  a  unit  economizer  and  about  100  feet  of  flue.  What  should  be  the 
draft  produced  by  the  chimney? 


Boiler  resistance 
Economizer  resistance 
100  ft.  flue      ... 
2  right  angle  bends 


.25 
.30 
.10 
.10 


Resistance  through  grate 44 


Draft  required 1.19 


270 


850 


230 


S-190 

b 

a 
I 
170 


«£ 


150 


130 


90 


110 


130 


150 


170 


190  210 

Height  of  Chimney 


230 


250 


270 


^^lor  or  Riley  underfed  stokers  the  air  is  delivered  through  the  fuel  bed  under  pressures 
of  4"  to  6"  of  water,  whatever  may  be  needed  to  maintain  a  balanced  draft  over  the  fire;  the  stack 
is  by  this  means  relieved  of  the  resistance  offered  by  the  fuel  bed  and  generally  gives  sufficient 
draft  to  pull  through  an  economizer. 

The  gases  after  leaving  an  economizer  are  cooled  and  the  draft  of  the  chimney  reduced  because 
of  the  lower  temperature. 

It  will  be  found  that  adding  25  feet  to  the  height  of  a  chimney  does  not  increase  the  draft  very 
much. 

The  dimensions  of  a  chimney  may  be  found  with  as  great  accuracy  as  is  required  by  means 
of  a  chart  which  has  been  constructed  from  the  tables  of  H.  P.  of  chimneys  given  by  Kent  and 


NOTES  ON   POWER  PLANT  DESIGN  29 

by  Christie  (See  Steam  Boilers,  Peabody  &  Miller).  On  this  chart  the  capacities  in  Ibs.  of  coal 
per  hour  per  square  foot  of  chimney  area  are  given  for  different  heights  of  chimney.  Knowing 
the  coal  to  be  burned  per  hour,  the  cross  sectional  area  for  any  assumed  height  may  be  calculated. 

The  ratio  of  height  to  cross  section  must  be  considered,  otherwise  a  poorly  proportioned  chim- 
ney may  be  obtained. 

For  discussion  of  the  stability  of  a  chimney  see  Steam  Boilers.  In  general  the  maximum  com- 
pression due  to  both  dead  load  and  wind  pressure  is  not  allowed  to  exceed  10  tons  per  square  foot. 


FEED    PUMPS    FOR    BOILERS 

STEAM   CONSUMPTION   OF  PUMPS 

• 

The  steam  consumption  of  a  duplex  pump  varies  with  the  speed  at  which  the  pump  runs 
At  half  speed  or  at  one-half  rated  capacity  125  to  150  pounds  of  steam  will  in  general  be  re- 
quired per  horse  power  hour  of  water  work  done. 

For  slower  speeds  the  rate  may  become  as  large  as  200  or  250  Ibs.  At  full  speed  and  at  rated 
capacity  90  to  100  pounds  is  a  fair  value  to  use  for  the  steam  consumption  per  water  horse  power 
per  hour. 

Turbine  driven  centrifugals  are  now  quite  generally  used  as  feed  pumps  in  the  larger  power 
plants. 

The  efficiency  of  a  centrifugal  pump  designed  for  a  given  head  and  given  capacity  may  reach 
80  Per  cent,  but  under  the  conditions  which  apply  to  centrifugals  used  as  feed  pumps  a  value  between 
0  and  55  per  cent  should  be  used.     The  steam  consumption  for  the  driving  end  may  be  obtained 
trom  the  curves  already  given. 


Drawings  and  table  of  dimensions  of  the  Terry  steam  turbine  with 
centrifugal  feed  pump  are  given  on  page  39. 


30 


NOTES  ON  POWER  PLANT  DESIGN 


THE  KNOWLES   HORIZONTAL  DOUBLE  ACTING   PLUNGER  PUMP. 

POT  VALVE  TYPE. 


End  packed  for  300  Ibs.  working  water  pressure. 
Center  packed  for  200  Ibs.  working  water  pressure. 


END  PACKED 


1 

i 

Capacity  per 

* 

§ 

fc 

S-g 

s  •§ 

s  I 

=Us 

mum  Speed 

SJ 
a  g 

1  -5 

«  "8 

o  S  £  ^ 

1  ° 

1  " 

«  5 

o     «5 

1  ° 

3 

*aJ 

fcmif5 

35 

* 

Strokes 

Gals. 

5 

a 

00 

Q 

4 

li 

5 

.11 

150 

161 

T 

T 

"ij" 

1 

57x10 

51 

3i 

7 

.25 

125 

31 

i 

i 

2 

H 

72x12 

6 

31 

7 

.33 

125 

41 

i 

i 

2 

U 

72x12 

71 

31 

10 

.47 

100 

47 

i 

u 

2 

U 

92x12 

71 

4J 

10 

.69 

100 

69 

i 

H 

21 

2 

92x12 

8 

5 

10 

.85 

100 

85 

i 

li 

3 

21 

92x12 

8 

4 

12 

.65 

100 

65 

i 

li 

21 

2 

112x12 

8 

5 

12 

1.02 

100 

102 

i 

u 

3 

21 

112x12 

10 

5 

12 

1.02 

100 

102 

u 

u 

3 

21 

112x12 

10 

6 

12 

1.47 

100 

147 

ii 

u 

31 

3 

112x22 

12 

6 

12 

1.47 

100 

147 

2 

21 

31 

3 

114x22 

12 

7 

12 

2.00 

100 

200 

2 

21 

5 

4 

120  x  27 

14 

7 

12 

2.00 

100 

200 

2 

21 

5 

4 

120  x  27 

14 

8 

12 

2.61 

100 

261 

2 

21 

6 

5 

124  x  27 

ie 

8 

12 

2.61 

100 

261 

21 

3 

5 

4 

124  x  28 

16 

8 

18 

3.91 

67 

261 

21 

3 

6 

5 

164  »  30 

16 

9 

18 

4.96 

67 

332 

21 

3 

8 

6 

164  x  30 

18 

9 

18 

4.96 

67 

332 

21 

3 

8 

6 

172  x  30 

CENTER  PACKED 


41 

21 

6 

.11 

150 

16.5 

1 

1 

U 

1 

68x10 

4J 

2| 

6 

.15 

150 

22.5 

1 

1 

li 

1 

68x10 

51 

3i 

7 

.25 

125 

31. 

I 

1 

2 

U 

72x12 

6 

31 

7 

.33 

125 

41. 

I 

L 

2 

11 

72x12 

61 

4| 

8 

.46 

125 

57.5 

I 

li 

21 

2 

75x12 

71 

41 

10 

.69 

100 

69. 

1 

u 

21 

2 

89x14 

8 

5 

10 

.85 

100 

85. 

1 

li 

3 

21 

89x14 

8 

5 

12 

1.02 

100 

102. 

1 

li 

3 

21 

96x14 

10 

6 

12 

1.47 

100 

147. 

u 

H 

31 

3 

98x22 

12 

7 

12 

2.00 

100 

200. 

2 

21 

5 

4 

100  x  27 

14 

8 

12 

2.61 

100 

261. 

2 

21 

5 

4 

102  x  27 

16 

9 

18 

4.96 

67 

332. 

21 

3 

8 

6 

136  x  30 

In  an  emergency  the  capacities  of  these  pumps  can  be  doubled.     For  continuous  work  such 
as  boiler  feeding,  speeds  and  capacities  one  half  of  those  given  are  recommended. 


NOTES  ON  POWER  PLANT  DESIGN 


31 


THE   VENTURI  METER 

Nearly  every  large  power  plant  has  a  Venturi  meter  in  the  boiler  feed  pipe.  This  meter  may 
have  a  recording  indicator  or  simply  a  Venturi  meter  manometer.  The  table  following  gives  the 
sizes  of  the  meters  for  boiler  feed  pipes  as  made  by  the  Builders  Iron  Foundry  of  Providence,  R.  I. 

The  Venturi  meter  manometer  contains  a  well  filled  with  mercury  into  which  a  glass  tube  dips. 
The  higher  pressure  from  the  inlet  of  the  Venturi  is  conducted  to  the  top  of  the  mercury  surface, 
and  the  lower  pressure  from  the  throat  of  the  meter  to  the  interior  of  the  glass  tube.  The  difference 
in  these  two  pressures  is  indicated  by  the  height  of  the  single  column  of  mercury  within  the  glass 
tube.  The  rate  of  flow  for  any  difference  of  pressures  can  be  read  opposite  the  surface  of  the  mer- 
cury of  the  inner  tube  from  the  graduated  scale  shown  at  the  left.  The  total  quantity  of  water 
flowing  may  be  obtained  by  taking  readings  periodically,  averaging  the  same  and  multiplying  the 
average  by  the  elapsed  time.  The  manometer  is  not  suitable  for  installations  where  the  rate  of 
flow  changes  rapidly.  For  such  cases  the  recording  indicator  shown  would  be  preferable. 


Extra  heavy  meter  tubes  with  "Manufacturers  Standard"  flange  ends  are  usually  selected 
for  hot  water.     These  are  ac'apted  to  pre  sures  up  to  250  pounds  per  square  inch. 


Inches 
Diameter 
of  Pipe 

Catalog 
Number 

Length 
of 
Meter  Tube 

Boiler  Horse  Power 

30IU.  perH.  P.  per  hour 

Pounds  per  Hour 

Gallons  per  Minute 

Minimum 

Maximum 

Minimum 

Maximum 

Minimum 

Maximum 

2 

25/8 
2?4 

21 

I'-ll/s" 

I'-IOV 
l'-7" 

45 
65 
115 

590 
850 
1500 

1360 
1960 
3470 

17600 
25400 
45100 

3 
4 
7 

35 

50 
90 

?L 

^2 

2J4A 
2KB 
2KC 

2'-45/8" 
2'-3" 
I'-IIK" 

85 
115 
180 

1150 
1500 
2350 

2660 
3470 
5420 

34500 
45100 
70400 

5 
7 
II 

70 
90 
140 

3 

31 
31* 

3IM 

2'-ll" 

2'-734" 

2'-4^n 

115 

180 
260 

1500 
2350 
3380 

3470 
5420 
7820 

45100 
70400 
102000 

7 
11 
16 

90 
140 
205 

4 

41* 

41H 
42 

4'-33/« 
3'-l07^n 
3'-6" 

180 
305 
465 

2350 
4000 
6000 

5420 
9170 
13900 

70400 
119000 
181000 

11 
18 
28 

140 
240 
360 

5 

51  5/8 

52 
52  V4 

5'-l?V 
4'-8'/^ 
4l-2n 

305 
465 
725 

4000 
6000 
9400 

9170 
13900 
21700 

119000 
181000 
282000 

18 
28 
4J 

240 
360 
560 

6 

62 
62  }< 
63 

5'-lln 

5'-4/2n 
4'-IOn 

465 
725 
1040 

6000 
9400 
13600 

13900 
21700 
31300 

181000 
282000 
406000 

28 
43 
63 

360 
560 
810 

8 

82  X 

M'A 
84 

7'-6Kn 
tf-llfc1 
6'-2n 

870 
1230 
1850 

11300 
16000 
24100 

26500 
36600 
55600 

344000 
476000 
722000 

53 
73 
III 

680 
950 
1440 

10 

MB* 

104 
105 

9'-4^B 
8'-7n 
7'-6" 

1230 
1850 
2900 

16000 
24100 
37600 

36600 
55600 
86900 

476000 
722000 
1129000 

73 
III 
174 

950 

1440 
2260 

12 

124 
125 
126 

II  '-0" 
9'-]  1" 
8'-  10" 

1850 
2900 
4200 

24100 
37600 

54200 

55600 
86900 
125000 

722000 
1129000 
1626000 

111 
174 

250 

1440 
2260 
3250 

32 


NOTES  ON  POWER  PLANT  DESIGN 


Graduated 
Scale 


*• 


Glass 
Tube 


Float 


CHART  RECORDER 

DIAL 

(Continuously  records  the" 
rate  of  flow) 


INDICATOR  DIAL 

(Shows  the  present  rate  of 
flow) 


DIMENSIONS,  Etc. 
Base  —  16  inches  square 
Height  —  6^  feet 
Shipping  Weight  —  500  Ibs. 


NOTES  ON  POWER  PLANT  DESIGN  33 

CALIBRATION  TESTS   ON   METERS   IN  SERVICE 

Test  No.  1.  Made  at  Worcester  Polytechnic  Institute  on  4-inch  meter  tube  No.  2319  1^ 
inch  throat,  equipped  with  manometer.  Water  was  pumped  through  the  meter  tube  into  a  very 
large  wooden  tank  resting  on  platform  scales,  which  form  a  part  of  the  regular  laboratory  equip- 
Ihe  manometer  was  placed  on  the  floor  immediately  below  the  meter  tube  to  which 
it  was  connected  by  flexible  pipes.  The  rated  capacity  of  this  meter  is  9,170  to  119  000  pounds 
per  hour.  The  results  were  as  follows: 

Cumbers                                            Pounds  of  Water  Per  Hour  Error  of  Meter 

Meter  Manometer  Actual  Weight        Manometer 

120,600  122,640  -  1.87% 

90,000  89,820  +0.20% 

59,950  59,940  +  0.02% 

4  and  5                                          30,000  29,370  +2.10% 

6and7                                            9,000  8,950  +0.55% 


(M  Te^°;  2\/°ur"inC,hTyenturJ,  Meter  (ll^~mch  throat)  at  the  plant  of  the  Woonsocket 
(Mass  )  Electric  Machine  &  Power  Company.  W;  ter  pumped  by  duplex  feed  pump  to  two  bar- 
rels which  were  filled  alternately,  the  weight  of  water  which  each  would  hold  having  been  deter- 
mined previously.  The  test  lasted  five  hours  and  the  flow  was  continuous. 

Corrected  weight  of  water  by  barrels         ...  132  802  Ibs 

Corrected  weight  of  water  by  Venturi        .         .         .         .         !         131^000  Ibs! 

Difference,  1.35%. 

Test  No.  3      Four-inch  Venturi  Meter  (1^-inch  throat)  at  plant  of  Brown  &  Sharpe  Mfg. 
Company,  Providence.     Meter  Tube   was  located  on  suction  side  of  single  plunger  pump  and 
1  water  was  from  two  calibrated  open  heaters  (emptied  alternately)  to  Meter  Tube  to  pump. 
Total  pounds  of  water  by  heaters     .          .          .  392  453  1DS 

Total  pounds  of  water  by  Venturi  Meter  .  397*104  Ibs! 

Difference,  1.18%. 
Duration  of  test,  10  hours. 

A  paper  prepared  by  Prof.  C.  M.  Allen  presented  before  the  A.  S.  M.  E.  gives  a  full  discus- 
sion ot  the  Venturi  Meter  as  applied  for  measuring  feed  water. 


34  NOTES  ON  POWER  PLANT  DESIGN 

ENGINES 


The  steam  consumption  of  a  simple  non-condensing  engine  varies  both  with  the  cut-off  and 
N\  ith  the  boiler  pressure. 

There  is  but  little  gain  in  raising  the  pressure  on  a  simple  engine  above  150  Ibs. 

The  variation  in  steam  consumption  per  I.  H.  P.  hour  with  the  cut-off  may  be  figured  with 
reasonable  accuracy  from  the  full  load  consumption  by  multiplying  the  full  load  consumption 
by  the  following  ratios: 

Load  M  Yi  Y±  Full          IK 

Ratio          1.26        1.13        1.09  1  1.05 

From  tests  on  engines,  of  about  the  same  type  and  size  as  the  engine  under  consideration, 
working  through  the  same  ranges  of  pressure  and  temperature,  from  the  same  initial  conditions, 
one  can  predict  the  probable  performance  with  reasonable  accuracy. 

In  the  absence  of  such  tests  the  cylinder  efficiency  of  a  single  valve  non-condensing  engine 
working  with  steam  under  150  Ibs.  absolute  may  be  taken  between  55  and  65  per  cent,  when  work- 
ing at  its  economical  load.  The  cylinder  efficiency  of  a  four  valve  condensing  engine  may  be  taken 
at  most  economical  load  as  from  66  to  72  per  cent.  The  size  of  the  engine,  the  valve  gear,  etc. 
all  have  an  influence  on  the  so-called  "cylinder  efficiency." 

This  cylinder  efficiency  multiplied  by  the  Rankine  efficiency  and  by  the  mechanical  efficiency 
gives  the  overall  efficiency  from  which  the  steam  consumption  may  be  calculated  as  explained  later 

CALCULATION   OF   POWER   OF   ENGINES 

The  mechanical  efficiency  of  an  engine  or  the  ratio  of  the  brake  power  to  the  indicated  horse 
power  is  between  90  and  93  per  cent. 

The  power  of  an  engine  at  any  speed  and  cut  off  may  be  found  by  drawing  an  indicator  card 
using  hyperbolae  for  expansion  and  compression  lines,  getting  the  M.  E.  P.  from  the  card  and 
then  proceeding  in  the  usual  way. 

For  a  compound  or  triple  expansion  engine  the  M.  E.  P.  is  calculated  on  the  assumption  that 
the  entire  pressure  drop  is  to  be  obtained  in  the  low  pressure  cylinder. 
The  ratio  of  cylinder  volumes  is 

for  compound  engines  H.  to  L.  1  to  2}/2  or  3 

in  some  rare  cases  1  to  7  or  8 

for  triple  expansion  engines  H.  to  I.  1  to  3 

I.  to  L.  1  to  3^  or 
or  H.  to  L.  1  to  9%  or 


A  calculation  for  Horse  Power,  which  will  give  results  more  or  less  in  error,  depending  upon 
the  accuracy  with  which  one  knows  the  multiplier  used  in  getting  the  actual  M.  E.  P.  from  the 
calculated,  may  be  made  as  follows  :  — 

H  p  =   Calculated  M.  E.  P.  x  multiplier  x  D2  X  .7854  x  2  x  Revs,  x  S 

33000 

D  =  dia.  low  pressure  cylinder  in  inches 
Revs.  =  revolutions  per  minute 

PI  =  absolute  initial  pressure  on  a  square  inch 
PZ  =  back  pressure  absolute  on  a  square  inch 

N  =  No.  of  expansions  = 


H2  x  cut  off 
Cut-off  is  expressed  as  a  decimal. 


NOTES  ON  POWER  PLANT  DESIGN  35 

S  =  stroke  in  feet 

H  =  dia.  high  in  inches 

Calculated  M.  E.  P.  =  -—-+^-2.3026  logw  N  -  Pt 

CYLINDER  EFFICIENCY   OF  STEAM  ENGINES  AND  STEAM  TURBINES 

The  ratio  corresponding  to  the  cylinder  efficiency  is  for  condensing  turbine  units  about  the  same 
(i.  e.,  .60  to  .72)  as  for  condensing  steam  engines;  for  non-condensing  turbine  units,  however,  the 
ratio  is  much  lower  than  for  non-condensing  engines,  the  value  being  .40  to  .49  as  against  .55  to  .65. 

The  higher  the  back  pressure  the  lower  the  ratio  becomes  and  .40  would  apply  for  pressures 
of  50  to  70  Ibs.  absolute  back  pressure,  .45  for  back  pressures  about  35  Ibs.  absolute,  and  .49  for 
back  pressures  of  15  to  20  Ibs.  absolute. 

From  these  figures  it  is  at  once  evident  that  the  non-condensing  turbine  working  against  back 
pressure  cannot  compete  in  economy  with  the  better  class  of  non-condensing  reciprocating  engines. 

It  is  the  custom  in  many  manufacturing  establishments  to  bleed  steam  from  some  stage  of 
a  turbine  or  from  a  receiver  between  the  cylinders  of  a  multiple  expansion  engine  and  to  use  this 
steam  for  industrial  purposes.  This  is  done  rather  than  to  draw  live  steam  from  the  boilers  through 
a  reducing  valve. 

It  is  also  customary  where  there  is  a  surplus  of  exhaust  steam  coming  from  the  auxiliaries 
or  in  other  words  more  steam  than  can  be  condensed  in  heating  the  feed  water  in  a  secondary  heater, 
to  exhaust  this  surplus  into  one  of  the  low  pressure  stages  of  the  turbine  or  into  the  second  receiver 
of  a  triple  engine  and  to  thus  get  additional  work  out  of  this  waste  steam. 

Where  steam  is  bled  in  this  way  a  valve  has  to  be  provided  to  prevent  steam  from  getting  back 
into  the  turbine  through  the  bleeder  opening  and  causing  the  turbine  to  run  away  when  under 
light  load,  at  which  time,  boiler  steam  taken  through  a  reducing  valve  would  be  fed  into  the  bleeder 
line  to  supply  at  reduced  pressure  the  steam  needed  for  industrial  purposes. 


RANKINE  EFFICIENCY  AND   CYLINDER  EFFICIENCY 

A  simple  calculation  for  a  bleeder  turbine  with  steam  withdrawn  at  one  of  the  higher  stages 
and  having  the  exhaust  steam  from  the  auxiliaries  sent  back  into  the  low  stage  will  serve  to  illus- 
trate the  method  of  getting  the  steam  consumption. 
Assume : 

2000  K.  W.  output  at  switchboard. 

Mechanical  Efficiency  of  Turbine,  92%. 

Generator  Efficiency,  93%. 

9000  Ibs.  steam  bled  out  per  hr.  at  36  Ibs.  abs. 

2000  Ibs.  exhaust  steam  per  hr.  with  1.7%  moisture  put  back  at  15  Ibs  absolute. 

What  is  the  steam  consumption  per  K.  W.  hour  with  boiler  pressure  177.5  Ibs.  ab.  97.3.  Sup. 
and  1  Ib.  absolute  pressure  in  condenser? 

Making  use  of  a  temperature  entropy  plot  or  diagram,  the  values  may  be  tabulated  as  below. 

Press,  ab.  Quality  Entropy  Heat  Contents  Heat  of  Liquid 

H  q 

177.5         97. 30  Sup.        1.62          1252.2 
36  .95  1.62          1120.6          230 

1  .807          1.62          904.8          70 


15  .983          1.73          1133.6          181.3 

1  .867          1.73          966  6          70 


36                                                 NOTES  ON  POWER  PLANT  DESIGN 
Rankine  eff.  =  —77 

it-  1    —  </2 

Hi  -  #2=  (Hi  -  g2)  X  Rankine  Eff.  =  heat  put  into  work  per  pound  in  non-conducting 

engine. 

(#,  -  #•>)  X  cylinder  eff.  =  heat  per  pound  of  steam  actually  put  into  work. 
'  1252.3  -"1120.6=  131.7 
131.7  x  .45  X  .93  X  .92  =  50.7  .45  =  cylinder  eff. 

33,000  X  60 
2545  = ^TO 


2545^1^00  =  6?  3  lbg    steam          K  w  hour  between  177.5  and  36  Ibs.  ab. 
50.7  x  746 


!33.7  K.  W.  developed  by  the  steam  before  it  is  bled. 
67.3 

1133.6  -966.6=  167 

167  x  .50  x  .93  x  .92  =  71.4 

A.  cylinder  efficiency  of  .5  has  been  used  because  of  the  moisture  in  the  steam. 

_2M5_x_L34_  =  lb     gteam         K  w  hour  between  15  jbs<  an(j  i  ib.  absolute. 

71.4 

2000 

-  =  42.0  K.  W.  recovered  from  exhaust  put  back  at  15  Ibs.  ab. 
47. 7o 

1252.3  -  904.8  =  347.5 

347.5  x.63,  x  .93  x  .92  =  187.3 

2545  x  1.34 
~18773~ 

2000  -  133.7  -  42  =  1824.3 
1824.3  x  18.21  =  33,220 
Steam  bled        =    9,000 

Total  steam  to  turbine  from  boiler  =  42,220 
Total  steam  to  condenser  =  33,220  +  2,000 

While  it  may  be  allowable  to  use  a  ratio  higher  than  .63,  in  this  case  .63  is  conservative. 

Although  efficiency  ratios  as  great  as  71.8  have  been  obtained,  in  general  the  ratio  actually 
realized  on  the  commercial  machine  is  lower. 

By  the  addition  of  extra  wheels  in  a  stage  or  of  extra  'stages  it  is  possible  to  get  the  high  ratios 
quoted,  as  the  loss  from  leakage  by  the  blades  is  thereby  reduced,  at  the  same  time  however  the 
cost  of  the  turbine  is  increased  and  it  becomes  a  question  as  to  whether  or  not  the  better  economy 
warrants  the  extra  expenditure  due  to  the  increased  first  cost. 

For  low  pressure  turbines  the  efficiency  ratio  for  machines  of  50  to  75  K.  W.  capacity  is  between 
50  and  55  per  cent. 

A  paper  read  by  Mr.  Francis  Hodgkinson  before  the  A.  S.  M.  E.  gives  the  steam  consumption 
of  Parsons  Turbines  under  different  conditions  of  pressure,  superheat  and  vacuua. 

As  this  data  may  be  found  useful  the  table  has  been  reproduced  here. 


3«»  IS  i  !g!  II 


a§5  :^S    S5  :S^.  :    «P  I   i2 

*"*       Z^fff    2*    IVjj    ;     w    I     eo 


;&&    2     *>? 
•      «T  !??      S 


•5   5 


•   • 


SS  =S 


§jj^  -^ 


«S!9 


132  :3 


« w    .mt- 

»0      -     -OHO 

"$7  :  •« 


^  i^-§  'cc"i3  iS^  i 


JI15 


. 
S8  :  • 


•sa  a 


:   E      S 


O          -05       0—.     -fft     ' 

SS«  :s  tes  its  :  = 


woo   -2     <~t- 
...   .J5     a,,. 


:   8      S 


|lp!gP 


:   S      3 


wS  '^S 

lisi  :  •* 


O  CO 

vt  *^ 


^  O  •     -  «'  Ji 

•• 


i 


.!« i* « iw  i  B  i « 

*KS  •«    ««  :o^  :    *•  I 
••   «•  •  .»     . 


8S2  :ft  3$:§21   2      I- 
.«  ««  jjs  :       I  a 


oogg  :8      :  :*.~  :R 

?a§  P    j  :s5  ja  s    s 


583  :       j  |Q   a 


'388  p  2g  :*3  i    s 


5  ;atf«  .    =5 


-s  :8S 
' 


t-^     :s 

So—  ;— - 


s  a 


-8  :8S    «'-.  :gc  :~ 

>28  :-3  §5  ISl  i   6      5 


SfcBalSn  sis 


jga  i  3  I  1 


38 


NOTES  ON  POWER  PLANT  DESIGN 


AN  ARTICLE  BY  A.  G.  CHRISTIE  IN  VOL.  34  A.  S.  M.  E.  TRANSACTIONS  CONTAINS  A  TABLE  GIVING 

ECONOMY  TESTS  OF  STEAM  TURBINES.     THIS  TABLE  GIVES  IN  THE  COLUMN  MARKED 

EFFICIENCY  RATIO,  THE  COMPARISON  WITH  THE  RANKINS  EFFICIENCY 

TABUS  2     ECONOMY  TESTS  Ol    HIGH  PRESSURE  STEAM  TURBINES 
EFFICIENCY  RATIOS   BASED  ON  EFFECTIVE  HORSEPOWER  MARKS  &  DAVIS  STEAM  TABLES  USED 


Maker  of  Turbine 

Type 

Date  of  Test 

Load-Kw. 

. 

a 

ft 
M 

Steam  Pressure 
Lb.  Absolute 

Temperature  at 
Throttle,  deg.  fahr. 

Vacuum  referred  to 
29.92'  Bar 

Condenser  Pressure, 
Lb.  Absolute 

I 

S 

a 

ijtf 

*3  i 

3K 

W 
•f 
W 

1 
a 

«' 

Heat  Utilized  per 
Lb.  of  Steam 

Heat  Available  per 
Lb.  of  Steam 

Efficiency  Ratio 

Reference 

ate  Briinner  M.  F.  G... 
ste  Brunner  M.  F.  G  .  .  . 
steBrUnner  M.  F.  G... 
;stinghouse  Machine  Co 
own  Boveri  &  Cie  
3te  Brunner  M.  F.  G... 

Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Curtis-Parsons 
Impulse-Parsons 

1910 

1910 
1910 

1910 
1911 
1910 

1911 
1911 

1910 
1909 

2128 
6000 
7442 
9173 
3053 
1416 
1750 
3764 
9830 
1495 
1271 
11466 
1250 
3320 
5128 
3585 

1500 
960 
960 
1800 
1360 
1260 
1500 
1500 
750 
3000 
3000 
750 
3000 
1500 
1000 
896 

156.2 
184.9 
192.0 
181.7 
150.2 
128.2 
176.4 
161.2 
192.2 
200.6 
172.1 
191.7 
184.9 
180.9 
171.2 
160.7 

482 
573 
584 
433 
505 
482 
586 
561 
475 
563 
568 
484 
573 
525 
565 
457 

27.89 
28.18 
28.18 
27.81 
29.00 
27.60 
27.08 
28.77 
27.22 
26.41 
27.31 
28.07 
27.89 
29.02 
28.52 
28.32 

0.995 
0;854 
0.853 
1.032 
0.456 
1.137 
1.392 
0.562 
1.322 
1.720 
1.278 
0.910 
0.996 
0.440 
0.726 
0.782 

13.82 
12.56 
12.625 
14.57 
13.01 
15.18 
14.23 
13.04 
15.15 
14.78 
14.61 
14.45 
14.32 
13.50 
14.35 
16.08 

16460 
15570 
15705 
16925 
15990 
18060 
17500 
16290 
17790 
17880 
17880 
17210 
17680 
16680 
17830 
19070 

247.0 
271.5 
270.2 
234.1 
262.2 
224.6 
239.5 
261.5 
225.2 
230.7 
233.5 
236.0 
238.2 
252.7 
237.7 
212.0 

343.8 
380.7 
384.4 
340.2 
385.5 
326.5 
354.8 
391.4 
336.0 
345.5 
354.3 
360.5 
373.1 
401.3 
382.9 
352.4 

71.8 
71.3 
70.3 
68.9 
68.0 
68.8 
67.5 
66.8 
67.0 
66.8 
65.9 
65.5 
63.9 
63.0 
62.1 
60.2 

Periodische  Mitteilungen 
Zeit.  D.V.D.  Ing.,   12/10/'10 
Periodische  Mitteilungen 
Trans.  A.S.M.E.,  vol.  32 
Dinglers  P.J.,  6/17/'ll 
Periodische  Mitteilungen 
Zeit.  F.D.G.  Turb.,  5/30/'ll 
Zeit.  F.D.G.  Turb.,  5/30/']l 
Trans.  A.S.M.E.,  vol.  32 
Data  from  Manufacturer 
Data  from  Manufacturer 
Trans.  A.S.M.E.,  vol.  32 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Zeit.  F.D.G.  Turb.,  5/30/'ll 
Stodola,  4th  ed.,  p.  449 
Zeit.  D.V.D.  Ing.,  12/10/'10 

istinghouse  Machine  Co 

swn  Boveri  &  Cie  
stinghouse  Machine  Co 
te  Brunner  M.  F.G  

)  wn  Boveri  &  Cie  

itfield,  Danek  &  Co  

Parsons 
Parsons 
Parsons 
Parsons 
Parsons 
Parsons 

1910 
1908 
1903 

1911 

6257 
4300 
3500 
3000 
5164 
3850 

1210 
1800 
1360 
1360 
1200 
1800 

203.7 
186.4 
156.4 
165.0 
214.3 
164.7 

559 
484 
499 
625 
509 
491 

29.02 
27.96 
28.84 
27.02 
28.95 
27.91 

0.440 
0.960 
0.532 
1.120 
0.473 
0.983 

11.95 
14.02 
13.71 
14.75 
13.18 
15.40 

14980 
16690 
16720 
18433 
16140 
18410 

285.5 
243.4 
248.5 
231.3 
258.7 
22L3 

415.0 
355.7 
378.6 
359.5 
402.3 
348.3 

68.8 
68.4 
65.6 
64.3 
64.3 
63.5 

Official  Test  Report 
Sibley  Jour,  of  Eng.,  1/11* 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Die  Turbine,  6/20/'ll 
Stodola,  4th  ed.,  p.  439 
Power,  l/2/'12 

is-Chalmers  

A.  Parsons  &  Co  

is-Chalmers  

E.  G  

Curtis-Rateau 
Cnrtis-Rateau 

1911 
1911 

6518 
6565 

1220 
1220 

198.7 
200.2 

601 
597 

29.28 
29.18 

0.352 
n.406 

11.43 
11.64 

14640 
14848 

298.4 
293.0 

434.2 
4-27.7 

68.7 
68.5 

Official  Test  Report 
Offirial  Test  Report 

E.  G  

ish  WestingLousc  

Curtis--Rate8U 
Curtis-Zoelly 
Curtis-Rateau  . 
Curtis-Rateau 
Curtis-Rateau 
Curtis-Rateau 
Curtis-Rateau 
Curtis-Zoelly 
Curtis-Rateau 

1911 

1909 
1910 
1908 
1911 
1907 

1911 

5066 
3584 
1545 
2477 
•4239 
2930 
3169 
2507 
3365 

1500 
1500 
1500 
1500 
1500 
1500 
1500 
1500 
1500 

190.2 
178.3 
188.5 
140.0 
188.3 
210.2 
184.7 
175.5 
171.0 

552 
569 
581 
522 
662 
568 
592 
460 
536 

28.68 
27.54 
28.59 
28.81 
29.11 
28.18 
29.11 
27.40 
26.00 

0.649 
1.166 
0.654 
0.588 
0.397 
0.894 
0.397 
1.234 
1.98 

13.00 
13.99 
12.97 
13.93 
11.97 
13.72 
12.74 
16.24 
15.09 

16100 
17190 
16230 
17135 
15620 
16935 
16230 
19020 
17970 

262.4 
243.7 
263.0 
244.8 
284.9 
248.7 
267.7 
210.0 
234.1 

391.5 
361.3 
396.3 
373.4 
439.0 
383.3 
425.1 
334.6 
381.3 

67.0 
67.5 
66.4 
65.6 
64.9 
64.9 
63.0 
62.8 
68.5 

Electrical  Review,  6/23/'ll 
Data  from  Manufacturer 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Elec.  Zeit.,  4/20/'ll 
Stodola,  4th  ed.,  p.  404 
Electrical  Review,  4/28/'ll 
Trans.  A.S.M.E..  vol.  32 
Data  from  Manufacturer 
Official  Test  Report 

A..  N  

fmann  

gtnann  

:.  G  

ish  Westinghouse  

:.  G  ..    . 

A.  N  

gmann  

ics  Howden  &  Son  
A.  N  

Zoelly 
Zoelly 
Zoelly 
Zoelly 
Zoelly 
Zoelly 
Rateau 
Zoelly 
Zoelly 
Zoelly 
Zoelly 
Zoelly 

1909 
1910 
1910 
19ia 
1908 
1910 
1911 

1908 

1910 
1910 

6383 
1400 
2052 
4189 
3000 
1250 
3166 
5118 
5000 
3540 
1641 
1235 

1000 
3000 
3000 
1000 
1000 
3000 
1500 
1000 
1000 
1500 
3000 
3000 

202.7 
180.7 
193.9 
179.7 
170.7 
182.1 
213.9 
133.7 
166.4 
155.1 
221.0 
176.8 

520 
554 
585 
557 
470 
582 
663 
549 
539 
469 
672 
451 

27.33 
27.40 
28.39 
28.66 
27.60 
28.82 
29.25 
27.55 
26.38 
28.21 
27.91 
28.39 

1.269 
1.237 
0.750 
0.618 
1.138 
0.540 
0.367 
1.161 
1.736 
0.838 
0.985 
0.750 

14.305 
14.21 
13.04 
13.30 
15.52 
13.09 
11.44 
15.18 
16.13 
15.07 
13.08 
15.35 

17150 
17310 
16290 
16520 
18278 
16500 
14970 
18530 
19350 
17940 
16775 
18156 

238.5 
240.0 
261.5 
256.5 
219.8 
260.2 
298.2 
224.6 
211.2 
226.3 
260.6 
222.3 

353.0 
356.2 
392.6 
391.3 
339.2 
404.5 
450.6 
341.6 
330.4 
349.5 
406.5 
357.8 

67.5 
67.4 
66.6 
65.5 
64.8 
64.4 
66.1 
65.7 
63.9 
64.8 
64.1 
62.2 

Engineer,  London,  10/29/'09 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Zeit.  F.D.G.  Turb.,  2/20/'ll 
Zeit.  F.D.G.  Turb.,  2/20/'ll 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Engineering,  10/20/'10 
Dinglers  P.J.,  7/15/'ll 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Dinglers  P.  J.,7/15/'ll 
Zeit.  F.D.G.  Turb.,  2720/'ll 
Zeit.  F.D.G.  Turb.,  2/20/'ll 

her  Wyss  &  Co  

her  Wyss  &  Co  

-{inghoffer  

A.  N  

likon  

her  Wvss  &  Co  

her  Wyss  &  Co.  .  <  

her  Wyss  &  Co  

her  Wyss  &  Co  

her  Wyss  &  Co  

tish  Thomson-Houston  . 
i.  Elec.  Co  

Curtis 
Curtis 
Curtis 
Curtis 
Curtis 
Curtis 
Curtis 
Curtis 
Curtis 
Curtis 
Curtis 

1911 

1909 
1906 
1909 

1911 

1911 
1910 

2987 
3464 
2500 
3000 
2236 
8880 
1541 
10816 
5095 
1221 
8775 

1500 

1500 
1500 
1500 

1500 
750 

3000 
750 

154.7 
210.0 
126.5 
191.3 
191.6 
192.5 
149.7 
190.0 
185.1 
134.7 
194.0 

505 
513 
414 
590 
654 
487 
365 
525 
554 
448 
451 

26.75 
28.75 
28.47 
29.05 
29.34 
28.02 
27.97 
29.39 
29.40 
27.16 
27.95 

1.557 
0.575 
0.711 
0.427 
0.284 
0.933 
0.956 
0.260 
0.255 
1.353 
0.956 

15.96 
13.62 
15.92 
12.79* 
11.77 
15.05 
17.46 
12.90 
12.71 
17.75 
*15.95 

18960 
16620 
18590 
16240 
15450 
17965 
19720 
16135 
16090 
20690 
18720 

213.7 
250.4 
214.0 
266.6 
289.8 
226.7 
195.3 
264.5 
268.4 
192.2 
213.8 

321.2 
393.4 
336.1 
420.4 
455.8 
359.5 
320.2 
427.3 
436.0 
314.0 
350.8 

66.5 
63.6 
63.7 
63.4 
63.6 
63.1 
61.0 
61.9 
61.6 
61.2 
61.0 

Engineering,  10/20/'ll 
Trans.  A.S.M.E.,  vol.  32 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Zeit.  D.V.D.  Ing.,  12/10/'10 
Trans.  A.S.M.E.,  vol.  32 
Engineering,  10/20/'H 
Trans.  A.S.M.E.,  vol.  32 
Trans.  A.S.M.E.,  vol.  32 
Engineering,  10/20  ''11 
Trans.  A.S.M.E.,  vol.  32 

tish  Thomson-Houston. 
E.G  

E.G  

i.  Elec,  Co  

tish  Thomson-Houston  . 
i.  Elec.  Co  

i.  Elec.  Co  

tish  Thomson-Houston 
i.  Elec.  Co  

References:   Zeit.  D.V.D.  Ing. — Zeitschrift  des  Vereines  Deutscher  Ingenieure;   Zeit.  F.D.G.  Turb. — Zeitschrift  iur  das  Ossammto  Turbinenwesen; 
Dinglers  P.J.— Dinglers  Polytechnisches  Journal;  Elec.  Zeit.— Electrotechnische  Zeitschrift. 


NOTES  ON  POWER  PLANT  DESIGN 

A 


39 


Discharge 


—  9O  ~/8O  Ga/.per  rh 


Port  /a/   End  and   Side    E/erations, 


Showing    change  in  steam 
connection    in    •sizes:  — 

/8O  -36O   6aj.  per  min. 
36O-S40     " 


/    Partial   End   and  Side 


•Showing    change   in  -si-earn 
connection  in   sizes  :  — 

S4-O  -72O   Ga/.  per  min 
72O  -/2OO     "       " 


Ga/.  per  m/n. 

9O-/80 

180-360 

360-S40 

SW-720 

7?o-&a 

Turbine 

i/' 

3 

9" 

A 

*E3L 

13.'     -!  3* 

e-/^ 

8'-6/ 

l/'-9&" 

12'  -/Of 

j" 

"£ 

I/" 

B 

2^S" 

^'-s" 

3'-  1  " 

4-'-7" 

4.  '-7" 

Exhaust  d/'a. 

•4-" 

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40  NOTES  ON  POWER  PLANT  DESIGN 

BLEEDING    STEAM 

In  many  cases  where  efficiency  is  based  on  coal  a  higher  plant  economy  may  be  obtained  by 
bleed  ing  some  of  the  steam  from  one  of  the  low  pressure  stages  and  using  this  steam  to  heat  the  feed 
water  instead  of  passing  all  of  the  steam  through  the  engine  or  turbine.  If  there  is  a  considerable 
amount  t>f  auxiliary  steam  available  to  heat  the  feed  water,  there  will  in  general,  be  no  need  of  bleed- 
ing steam  from  one  of  the  stages,  as  the  auxiliaries  will  usually  furnish  enough  exhaust  to  raise 
the  temperature  of  the  feed  water.  In  some  pumping  stations,  however,  where  the  circulating 
water  passing  through  the  condenser  does  not  have  to  be  pumped  by  a  special  pump,  the  number. 
of  auxiliaries  in  use  is  reduced  and  the  steam  available  for  heating  the  feed  water  is  small  in  amount. 
In  such  cases  it  may  be  advisable  to  bleed  steam  from  one  of  the  stages  where  the  pressure  is  approx- 
imately 5  Ibs.  above  the  atmosphere.  The  equation^  for  calculating  efficiency  where  steam  is  bled 
and  where  steam  is  not  bled,  follow:  The  percentage  to  be  bled  may  be  anywhere  from  2  to  as  much 
as  10  per  cent  depending  upon  conditions.  The  temperature  of  the  feed  water  cannot  of  course, 
be  heated  to  a  higher  temperature  than  that  of  the  steam  bled  from  the  turbine. 

Subscript  1  =  boiler  condition. 

qi  +  XiTi  =  Hi 
Subscript  2  =  condition  at  lowest  back  pressure  or  pressure  in  condenser. 


Subscript  b  =  condition  at  point  where  bleeding  takes  place. 
qf  +  xbrb  =  Hb 

W  =  total  steam  per  H.  P.  hour,  different  in  amount  for  Cases  A  and  B. 
B  =  Steam  bled  per  H.  P.  hour. 
W  —  B  =  Steam  through  condenser  per  H.  P.  hour. 

qh  =  heat  of  liquid  of  condensed  steam  leaving  condenser. 

This  water  is  about  7  degrees  lower  than  the  temperature  corresponding  to  the  vacuum  in 
condenser. 

q/  =  heat  of  liquid  of  feed  water. 

Assume  60  per  cent  cylinder  efficiency. 

CASE  A 
No  STEAM  BLED 

2545  •*•  .60  (Hi  -  H2)  =  steam  per  H.  P.  hour  to  be  supplied  by  boiler. 

.60  (Hi  -  HJ  =  heat  transformed  into  work  per  pound  of  steam  supplied. 

CASE  B 

SOME  STEAM  BLED  FROM  ONE  OF  THE  LATER  STAGES  AND  UTILIZED  TO  HEAT 

THE  FEED  WATER 

2545  -  60  J  per  Cent  through  turDine  to  condenser  x  (#1  -#2) 
\  100 

Per  cent  bled  (Hi  -  Hb)  } 

JQQ  —  -  f  =lbs.  steam  per  H.  P.  hour  =  W. 

60  I  Per  cent  through  Per  cent  bled  ,  1 

100  '  \Hl  ~  Hi)  +  -      -^OQ  --  (Hl  -  Hb)        =  B.  T.  U.  which  are 

transformed  into  work  per  pound  of  steam. 


NOTES  ON   POWER  PLANT  DESIGN  41 

W  (Hi  -  qf)  =  B.  T.  U.  per  H.  P.  hour  to  be  supplied  by  the  boiler. 

Efficiency  Case  B  =  -fjr-TTF  --  T~ 


W 


(W  -  B)  (qj  -  qh)  =  B^H,  -  .6  (Hl  -  Hb)  -  qt\ 
Wqf  =  (W  -  B)  qh  +  B  (Hb)  +  .40  (H,  -  Hb)  x  B 

Therefore  efficiency  Case  B  = 


WHl  -  (W  -  B)  qh  -  BHb  -  .40  B  (H,  -  Hb) 


Efficiency  Case  A  =  -^rjjr— 


W  (Hl  -  qh) 


B.  T.  U.  put  into  work  per  pound  of  steam. 
Case  A        .60  (Hl  -  H2) 


CaseB  (H|_H2)-(Hi_ 

(1)  Difference  A-B     .60  (  l-^j^-  j  (Hl  -  H2)  -  ^  <*,- 

„     .60  (per  cent  bled)  ,  TT 
Case  A  utilizes  per  Ib.  -  —  -  -  (Hb  —  Hz)  more  heat  units  than  Case  B. 

The  heat  to  be  supplied  by  the  boiler  per  pound  is 
Case  A  =  Hi  -  qh 

%  through        .40%  bled  ,_,        „  .       %bled 
Case  B  =  Hl  -  qf        qf=  fr-—^-   ~  +  -    -  ^Q~~  (Hl  ~  Hb^  +  '    100  --  Hb 

r»*o  -R      77        %  through  .40%  bled  %  bled 

=  Hl  "    "^oo~     qh~   "100"  '  (Hl  ~  Hb}     ~Tdo~~^6 

/%  through  .40%  bled  fu  %  bled       „ 

(2)  Case  A  —  Case  B  =  (  ^  ~1QO         "    ^  q      --  100  ---  ^    l  "     b^  +       100  ---     b 

.40%  bled  „         %  bled          %bled 

~~     (Hl  ~  Hb}     ~        qh  +  "       Hb 


—  (Hi  -Hb)  +       Tnrp  (Hb  -  qh)  which  is  the  difference  in  the  heat  supplied 

by  the  boiler  per  pound  of  steam 


42  NOTES  ON  POWER  PLANT  DESIGN 

GENERAL  DIMENSIONS   OF   ENGINES 

Tables  of  cylinder  sizes,  horse  power  and  overall  dimensions  of  a  number  of  different  engines 
are  given  on  the  pages  following. 

The  engines  shown  are  each  typical  of  a  class  and  have  been  selected  with  this  in  mind  only. 
In  general  the  single  cylinder  engines  are  rated  on  a  cut-off  at  about  one  quarter  stroke. 


NOTES  ON  POWER  PLANT  DESIGN 


43 


WATER  RATES   OF  SMALL  TURBINES 

The  water  rates  of  small  turbines,  exhausting  against  atmospheric  pressure,  based  on  test  are  shown  by  the 
accompanying  plots  taken  from  an  Article  by  G.  A.  Orrok  in  Vol.    31  of  Transactions  of  A.  S.  M.  E. 

r-5000-,  10000 


120  —         160 
Brake  Horse  Power 


STEAM  CONSUMPTION  CURVES,  BLISS  TURBINE,  NON-CONDENSING 


40         60 


80         100        120        143 
Brake  Horse  Power 


160        180       200 


TESTED    BY   P.    L.    PRYOR   AT   HOBOKEN,   N.   JT. 

O  =  Two-nozzle,  X  =  Four-nozzle 


LOAD  CURVES  OF  KERR  TURBINE 

24-IN.  WHEEL,  8-STAOE  175-LB.  OAQE  PRESSURE,  NON-CONOEN8INO 


1500 


10  15 

Brake  Horse  Power 


Water  Rate-Pounds  per  h.p_-hr. 

S  £  8  8  j 

Water-Rate 

//* 

now 

>OM    * 

28"            2 

5*           27.5' 

20  \^ 
sT 

W>' 

§ 

a 

<& 

<.$&•*/* 

/ 

> 

<yr/' 

2000  | 
1000  H 

^ 

^ 

"*~ 

50 


100  150 

Brake  Horse  Power 


200 


250 


STEAM  CONSUMPTION  CURVES,  STURTEVANT  TURBINE 

20-IN.    WHEEL.     SINGLE-STAGE,     NON-CONDENSING,     2400     R.P.M. 

70 


STEAM  CONSUMPTION  CURVES,  24-iN.  KERR  TURBINE 

SIX-STAGE.    CONDENSING,   VARYING    VACUUM,    70-LB.    GAGE    PRESSURE 
3500 


STEAM  CONSUMPTION  CURVES,  TERRY  TURBINE 

24-IN.  WHEEL,  150-LB.  PRESSURE.  NO  SUPERHEAT,  NON-CONDBNSmG.  TESTED  BY  WE6TINOHODSE 

MACHINE  co.,  prrrsBURO,  PA. 


3000 


10  20  30  40  50  60  70 

Brake  Horse  Power 

STEAM  CONSUMPTION  CURVES,  50  H.P.  CURTIS  TURBINE 

ONE-PRESSURE-STAGE,  THREE    ROWS    OF  BUCKETS,    25$-IN.     WHEEL,     CURVES    CORRECTED    TO 
I&0-LB.  BOILER     PRESSURE,     NO    SUPERHEAT,     ATMOSPHERIC     EXHAUST 


•9    40 


tat  Switchboard)  y>  Load         \  Load     Full  Lend      J-4 


100  200 

Turbine  Brake  Horse  Power 


CONSUMPTION  CURVES,  200-H.p.  CURTIS  TURBINE 


THREE-STAGE,  36-IN.  WHEEL,  CORRECTED  TO  165-LB.  ABB.  BOILER  PRESSURE,    NO  SUPERHEAT, 
NON-CONDENSING 


Curve 
A 
B 
C 
C' 
D 
E 
E' 


Type 

Sturtevant 
Terry 
Bliss 

Ken- 
Curtis 


R.P.M.     Rated  H.P. 


2,400 
2,350 
2,600 
2,600 
2,800 
3,600 
2,000 


20 
50 
100 
200 
150 
50 
200 


Steam  Press.-150  Lb. 
Dry  Steam 
Atmospheric  Exhaust 


Load 
ECONOMY  CURVES  OF  SMALL  TURBINES 


NOTES  ON  POWER  PLANT  DESIGN 


45 


SKINNER   CENTRE   CRANK   AUTOMATIC 
OILING   ENGINE 


SIZE  OF 
ENGINE. 

Rating. 

Constant. 

WHEELS. 

Pipes. 

Belted. 

Direct  Connected. 

CAPACITY 
OP 

DYNAMO. 

Diam. 
Inches. 

Belt 
Pulley 
Width. 
Inches. 

Steam. 

Exhaust. 
Inches. 

Length. 
Ft.    Ins. 

Width. 

Ft.    Ins. 

.Length. 
Ft.    Ins. 

Width. 
Ft.    Ins. 

8    xlO 

55 

.00253 

48 

9 

2% 

3 

7    7 

4    9 

7    7 

6    10 

20—  30 

9     xlO 

60 

.00321 

48 

9 

3 

3% 

7    7 

4    9 

7    7 

7 

26—  35 

10      XlO 

70 

.00396 

54 

11 

3% 

4 

8    7 

4  10 

8    8 

7       2 

35—  40 

11     xlO 

80 

.00479 

54 

11 

3% 

4 

8    7 

4  10 

8    8 

7    5 

40—  45 

8    x!2 

55 

.00304 

48 

9 

2% 

3 

7     8 

4  10 

7    8 

6  10 

20—  30 

9     x!2 

60 

.00385 

48 

9 

3 

3% 

7     8 

4  10 

7     9 

7    4 

25—  35 

10     x!2 

70 

.00476 

54 

11 

3% 

4 

8    8 

4  11 

8    8 

7    4 

85—  40 

11     x!2 

80 

.00575 

54 

11 

3% 

4 

8    8 

4  11 

8    9 

7    5 

40—  50 

HXx  12 

80 

.00629 

54 

11 

3% 

4 

8    8 

4  11 

8     9 

7     9 

45—  50 

12     x!2 

100 

.00685 

60 

13 

4 

5 

10 

5     1 

10    6 

8    4 

50—  60 

13     x!2 

135 

.00804 

60 

13 

4% 

6 

10     1 

5    2 

10     7 

8    6 

60—  76 

14    x!2 

135 

.00932 

60 

1.3 

4% 

6 

10    1 

5    2 

10     7 

8    6 

60—  75 

10    xlo 

80 

.00595 

60 

13 

3% 

4% 

10 

5     1 

10    6 

8    4 

50 

11     x'15 

80 

.00719 

60 

13 

3% 

4% 

10 

5     1 

10    6 

8    4 

50 

12     xlo 

100 

.00856 

60 

13 

4 

5 

10 

5     1 

10    6 

8    4 

50 

13     x  15 

135 

.01005 

60 

13 

4% 

6 

10     1 

5    2 

10    7 

8    6 

60—  75 

14     xlo 

135 

.01166 

60 

13 

4% 

6 

10     1 

5    2 

.10     7 

8    6 

60—  75 

15     x!6 

180 

.01427 

66 

15 

5 

6 

12 

6    8 

12    7 

10    4 

100 

16     x!6 

180 

.01624 

66 

15 

5 

6 

12 

6     8 

12    7 

10    4 

100 

17     x!6 

200 

.01833 

66 

15 

5 

6 

12 

6.    8 

12    7 

10    4 

100—125 

18     x!6 

270 

.02055 

78 

17 

6 

8  • 

13    6 

7    4 

14    9 

11     3 

125—150 

12     x!8 

120 

.01028 

72 

14% 

4 

5 

12     1 

6    6 

12    5 

10 

75 

14     x!8 

140 

.01399 

72 

14% 

4% 

6 

12     1 

6    6 

12    5 

10 

75 

15     x!8 

180 

.01606 

72 

16% 

5 

6 

12    3 

6  10 

12    7 

10    4 

100 

16     x!8 

180 

.01827 

72 

16% 

5 

6 

12    3 

6  10 

12    7 

10    4 

100 

17    x!8 

200 

.02063 

72 

16% 

5 

6 

12    3 

6  10 

12    7 

10    4 

100—125 

18     x!8 

280 

.02313 

78 

19 

6 

8 

13    6 

7    6 

14    9 

11     5 

125—150 

19     x!8 

280 

.02577 

78 

19 

6 

8 

13    6 

7    6 

14    9 

11     5 

150 

20    x!8  • 

280 

.02856 

78 

19 

6 

8 

13    6 

7    6 

14  11 

11     7 

150—175 

18    x20 

300 

.0257 

84 

21 

6 

8 

14  10 

8    5 

16    6 

12  10 

175—200 

19    x20 

300 

.02863 

84 

21 

6 

8 

14  10 

8    5 

16    6 

12  10 

176—200 

20    x20 

300 

.03173 

84 

2i 

6 

8 

14  10 

8    5 

16    6 

12  10 

175—200 

21     x20 

350 

.03498 

84 

23 

7 

10 

14  11 

8    7 

16  10 

12  11 

200 

22    x20 

350 

.03839 

84 

23 

7 

10 

14  11 

8    7 

16  10 

12  11 

200 

18    x24 

300 

.03084 

84 

21 

6 

8 

15    3 

8    6 

17    2 

11     6 

175—200 

19    x24 

300 

.03436 

84 

21 

6 

8 

15    3 

8    6 

17    2 

11     6 

175—200 

20    x24 

320 

.03808 

84 

21 

6 

8 

15    3 

8    6 

17    2 

11     6 

200 

21     x24 

350 

.04198 

84 

24 

7 

10 

15    4 

B    9 

17     4 

11     8 

200 

22    x24 

3-30 

.04607 

84 

24 

7 

10 

15    4 

8     9 

17    4 

11     8 

200 

46 


NOTES  ON  POWER  PLANT  DESIGN 
SKINNER  ENGINE 


SIZE  OF 
ENGINE. 

Revolutions 
per 

Minute. 

INITIAL  PRESSURES. 

SIZE  OF 
ENGINE. 

Revolutions 
per 
Minute. 

INITIAL  PRESSURES. 

70 

80 

90 

100 

110 

120 

7O 

80 

90 

100 

110 

120 

8  xlO 

300 
325 
.  350 

27 
29 
31 

31 
33 
36 

34 
37 
40 

38 
41 
44 

42 
45 

49 

46 
50 

53 

13x12 

250 
275 
300 

70 

77 
84 

80 
89 
97 

91 
100 

109 

101 
111 

121 

111 
122 

133 

121 
133 

9  xlO 

300 
325 
350 

34 
37 
39 

39 
42 
45 

43 
47 
61 

48 
52 
56 

„  53 
57 
62 

68 
63 

14x12 

250 
275 
300' 

82 
90 
99 

93 
103 
112 

105 
116 
126 

117 
128 
140 

128 
141 

140 

10  xlO 

300 
325 
350 

42 
45 

49 

48 
52 
56 

54 
58 
62 

60 
64 
69 

65 
71 

71 

10  x  Iff 

225 
250 

275 

47 
52 
57 

54 
60 
65 

60 
67 
74 

67 
74 
82 

74 

82 

80 

11  xlO 

300 
325 
350 

50 
55 
69 

68 
62 
67 

66 
70 
76 

72 
78 
84 

79 
86 

86 

11x15 

225 
250 
275 

57 
63 
69 

65 
72 
79 

73 

81 
89 

81 

90 

89 

6  x!2 

250 
275 
300 

27 
29 

32 

31 
34 

37 

34 
38 
41 

38 
42 
46 

42 
46 
50 

46 
50 
55 

12x15 

225 
250 
275 

67 
75 
83 

77 
86 
94 

87 
96 
106 

96 
107 

106 

9  x!2 

250 
275 
300 

34 
37 
41 

39 
42 
46 

43 
48 
52 

48 
53 
58 

63 

58 
64 

58 
64 

13  x  15 

225 
250 
275 

79 
88 
97 

90 
101 
111 

102 
113 
124 

113 
120 
138 

124 
138 

136 

10  x!2 

250 
275 
300 

42 
46 
50 

48 
62 

57 

54 
59 
64 

60 
66 
71 

66  . 

72 

71 

14  x  15 

225 

250 
275 

92 
102 
112 

105 
117 
128 

118 
131 
144 

131 
146 
160 

144 
'  160 

157 

11   x!2 

250 
275 
300 

50 
55 
60 

58 
64 
6'J 

65 
71 
78 

72 
79 
86 

79 

87 

86 

15x16 

210 
230 
250 

105 
115 
125 

120 
131 
143 

135 
148 
161 

150 
164 
178 

165 
181 

180 

Il>/xl2 

250 
276 
300 

55 
61 
66 

63 
69 
76 

71 

78 
85- 

79 

87 

87 

16  x  10 

210 
230 
250 

119 
131 
142 

136 
149 
162 

154 
108 
183 

171 
187 
203 

188 
205 

205 

12  x!2 

250 
275 
300 

60 
66 
72 

69 
75 
82 

77 
85 
93 

86 
94 
103 

94 
104 

103 

17x16 

210 
230 
250 

135 
148 
160 

154 
169 
183 

173 
190 
206 

193 
211 
229 

212 
232 

231 

18  x  1C 

210 
230 
250 

150 
165 
180 

173 
189 
206 

194 
213 
231 

216 
236 
257 

237 
260 
283 

259 
284 

19x20 

160 
180 
200 

160 
180 
200 

183 
206 
229 

206 
232 
258 

229  • 
258 
286 

252 
283 
316 

275 
309 

12  x  18 

175 
200 
225 

63 

72 
81 

72 
82 
93 

81 
93 
104 

90 
103 
116 

99 
113 
127 

108 
123 

20x20 

160 
180 
200 

178 
200 
222 

203 
229 
254 

229 
257 
286 

254 
286 
317 

279 
314 

305 

14  x  18 

175 
200 
225 

86 
98 
110 

98 
112 
126 

110 
126 
142 

122 
140 
157 

135 
154 

147 

21x20 

160 
180 
200 

196 
220 
245 

224 
252 
280 

252 
283 
315 

280 
315 
350 

308 
346 

336 

15  x  18 

175 

200 
225 

98 
112 
127 

113 
129 
145 

127 
145 
163 

141 
161 
181 

155 
177 

169 

22x20 

160 
180 
200 

215 
242 
269 

246 
276 
307 

276 
311 
346 

307 
346 
384 

338 
380 

369 

10  x  18 

175 

200 
225 

112 
128 
144 

128 
146 
165 

144 

165 
185 

160 
183 
206 

176 
201 

192 

18  x  24 

140 
150 
165 

151 

102 
178 

173 

185 
204 

194 
208 
229 

216 
231 
255 

237 
254 
280 

259 
278 
305 

17  x  18 

175 
200 
225 

126 
144 
162 

144 
165 
186 

163 
186 
209 

181 
206 
232 

199 
227 

216 

19x24 

140 
150 
165 

168 
180 
198 

192 
206 
227 

217 
232 
255 

241 

258 
284 

265 
284 
312 

289 
309 

18  x  18 

175 
200 
225 

142 
162 
182 

162 
185 
208 

182 
208 
234 

202 
231 
260 

223 
254 
286 

243 

278 

20x24 

140 
150 
165 

187 
200 
220 

213 
229 
251 

240 
257 
283 

267 
28(7 
314 

293 
314 

320 

19  x  18 

175 
200 
225 

158 
180 
203 

180 
206 
232 

203 
232 
261 

.226 
258 
290 

248 
284 

271 

21x24 

140 
150 
165 

206 
220 
242 

235 
252 

277 

265 
283 
312 

294 
315 
346 

323 
346 

352 

20  x  18 

175 
200 
225 

175 
200 
225 

200 
229 
257 

225 
257 
289 

250 
286 

275 

22x24 

140 
150 
165 

226 
242 
266 

258 
276 
304 

290 
311 
342 

323 
346 
380 

355 
380 

387 

18  x  20 

160 
180 
200 

144 
162 
180 

165 
186 
206 

185 
208 
231 

206 
231 
257 

226 
254 
283 

247 
278 
308 

18  x  24  —  22  x  24,  Side  Crank  only. 
18  x  20  —  22  x  20,  Center  Crank  only. 
All  others,  Side  or  Center  Crank. 

NOTES  ON  POWER  PLANT  DESIGN 


47 


AMERICAN   BALL   DUPLEX  COMPOUND   ENGINE 
FOR   DIRECT   CONNECTED   SERVICE 


—  H J 


Horse- 
power 

K,  W. 

Cylinder 
Diameters  and 
Stroke 

Revolutions 
per 
Minute 

General  Dimensions  in  .Inches 

Shipping  Weight 
in  Pounds 

Floor  Space 

Wheels 

C 

D 

E 

f 

H 

Steam  nnd 
Exhaust  Pipes 

Direct- 
con- 
nected 
Engine 

Engine 
and 
Dynahio 

Length 

Width 

Dia. 
A 

Width 
B 

Steam 

Exhaust 

80 

50 

9>£&15   x    11 

275  to  300 

m/2 

94# 

60 

11 

16 

34# 

87^ 

35'/2 

27# 

3# 

5 

11,600 

19,800 

120 

75 

11  J4&  18^x12 

260  to  290 

my2 

109j^ 

66 

13 

18 

39 

97^ 

98/2 

28^ 

4 

6 

15.350 

25,350 

160 

100 

13  &  20  x   14 

240  to  260 

144X 

114# 

72 

15 

20^ 

43X 

108X 

42^ 

33 

4^ 

.     7 

21,500 

33,100 

200 

125 

14  &  22  x  16 

220  to  240 

157 

125* 

78 

17 

21  X 

46# 

118 

45 

36^ 

5 

8 

24,500 

39,300 

250 
325 
400 

150 
200 
250 

16  &  25  x   16 

18  &  28   x   18 
20  &  32  x   18 

210  to  230 
190  to  210 
180  to  200 

164# 
179^ 

184 

132^ 
147 
157 

84 
84 
90 

19 
23 
25 

23# 
26 
28 

48^ 
54 
57 

m% 

WA 
139 

45 
45 
48 

42 
49 
54 

6 

6 

7 

9 
10 

12 

31,700 
39,500 
48,000 

48,200 

NOTE— The  cylinders  mentioned  in  this  table  are  adapted  for  100  pounds  steam  pressure,  non-condensing.    For  other  conditions  the  cylinders-- 
will be  varied  to  give  best  economy. 


48 


NOTES  ON  POWER  PLANT  DESIGN 


THE  AJAX  ENGINE,  MADE   BY   HEWES   &   PHILLIPS 

NON   RELEASING   CORLISS   VALVE   GEAR  FOR   DIRECT 

CONNECTING   UNITS 


Diameter 

Pulley 

Approximate 
Floor  Space 

From 
Center  ot 

From 

From 

Con- 

Initial Pressure 
in  Pounds 
100     |      125      1      15° 

Size  of 
Engine 

Revo- 
lutions 

Initial  Pressure 
in  Pounds 
100     |      125      |      150 

Cubic 
Feet  in 
Foundation 

licked 

Engine  to 
Center  of 
Back 
Bearing 

Center  of 
Crank-shaft 
to  end  of 
Cylinder 

Center  of 
Engine  to 
Floor 

stant 
Based 
on  i 
Pound 
M.E.P. 

Steam 

Exhaust 

Dia- 
meter 

Face 

Length 

\Vidtl. 

Kilowatts 

Inches 

Horse-power 

Inches 

Inches 

Inches 

Inches 

Ft.      Ins. 

Ft.     Ins. 

Ft.     Ins. 

Ft.     Ins. 

Ft.  Ins. 

i  Rev. 

58 

72 

88 

12       X  15 

225 

86 

I  08 

132 

4}£ 

6 

72 

16 

252 

"       7 

6      o 

4    6 

8        0 

2 

.0085 

66 

85 

104 

'3     x  '5 

225 

100 

127 

156 

5 

6 

72 

16 

260 

ii       7 

6      o 

4     6 

8      o 

2 

.OIOO 

73 

9' 

112 

225 

no 

137 

1  68 

5 

6 

72 

16 

260 

'I       7 

6      o 

4     6 

8      3 

2 

.0108 

79 

95 

120 

14     x  15 

225 

118 

147 

181 

5 

6 

72 

16 

270 

ii       8 

6      5 

S    ° 

8      3 

2 

.OIl6 

105 

129 

14^x15 

225 

125 

'57 

'93 

5 

6 

72 

16 

270 

ii       8 

6      5 

5    ° 

S      5 

2 

.0124 

90 

"3 

140 

15     x  15 

225 

'35 

170 

2IO 

6 

7 

72 

16 

280 

II        IO 

6      7 

5     ' 

8      5 

- 

•0134" 

100 

129 

1  60 

16     x  15 

22S 

150 

'93 

237 

6 

7 

72 

16 

280 

II        10 

6      7 

5     l 

S       S 

2 

.0152 

83 
9° 

105 

112 

129 
138 

14     x  16 

14^x16 

225 
22S 

125 
'35 

Z 

'93 

207 

6 
6 

7 

7 

72 
72 

16 
16 

270 

270 

ii       8 
n       8 

6       5 
6      5 

5    ° 
5    ° 

O         O 

9       o 

2 

.0124 
•0'33 

96 

I  2O 

ISO 

15     x  16 

225 

'45 

181 

223 

6 

7 

72 

16 

290 

I  1        IO 

6      7 

5     ' 

9       2 

2 

.0143 

106 

136 

I67 

16     x  16 

225 

160 

204 

25' 

6 

7 

72 

18 

290 

II        10 

6      9 

5    2 

9       2 

2 

.Ol6l 

I23 

'54 

190 

17     x  16 

225 

,85 

231 

286 

6 

7 

72 

18 

200 

I  I        IO 

6      9 

5     2 

9      4 

2 

0183 

"3 

'43 

'73 

16     x  18 

2IO 

170 

215 

265 

6 

7 

78 

20 

300 

'3       5 

7       7 

6    o 

9       6 

2 

.0182 

'3° 

162 

200 

17      x  18 

2IO 

•95 

244 

300 

6 

7 

78 

22 

320 

•3      5 

7       9 

6     i 

9       6 

2 

0206 

'43 

181 

223 

18     xi8 

2IO 

215 

272 

335 

6 

7 

78 

24 

33° 

'3      5 

7     n 

6    3 

9       8 

2 

.0230 

160 

202 

269 

19     x  18 

2IO 

240 

304 

404 

7 

8 

78 

26 

360 

•3      5 

8     10 

7     o 

9      8 

2 

.0257 

178 

225 

276 

20     x  18 

210 

268 

338 

4i5 

7 

8 

78 

28 

420 

•3      8  . 

9      ° 

7     3 

9     10 

2 

.0285 

130 

162 

200 

17     xi9 

200 

'95 

245 

301 

6 

7 

84 

24 

43° 

'3     " 

7   •  ii 

6    3 

0         O 

2 

.0217 

150 

182 

225 

18     x  19 

200 

220 

274 

337 

6 

7 

84 

25 

44° 

'3     'i 

8       o 

(>    3 

0        O 

2 

.0243 

1  60 

204 

251 

19     x  19 

2OO 

240 

306 

376 

7 

8 

84 

26 

45° 

'3     " 

8     10 

7     o 

0          2 

2 

.0271 

180 

226 

278 

20     x  19 

200 

270 

340 

418 

7 

8 

84 

26 

460 

'3     I' 

8     10 

7     ° 

o      6 

2 

.0301 

•53 
170 

192 
2'5 

236 
264 

18     x  20 

19       X  20 

20O 
200 

230 
255 

289 
322 

355 
39° 

6 
6 

7 
7 

84 
84 

26 
28 

47° 
480 

14     10 
14     10 

S          2 

9      *° 

6     5 
7     3 

o      8 

o      S 

2 

.0256 
.0285 

190 

238 

293 

2O       X  20 

2OO 

285 

358 

440 

7 

8 

84 

3° 

500 

14     10 

9       2 

7     4 

0       10 

2 

•0317 

206 

262 

323 

21       X  2O 

2OO 

3IO 

394 

485 

7 

8 

84 

32 

500 

14     10 

9       - 

7     4 

I          O 

2 

•0349 

HORSE-POWER.  —  In  the  computation  of  the  power  of  an  engine,  the  prime  factors  are  area  of  cylinder,  pressure  of  steam,  piston  speed,  and  point  at  which 
steam  is  cut  off.  Our  calculations  of  horse-power,  as  indicated  in  the  above  table,  are  based  upon  ari  initial  steam  pressure  of  100,  125  and  1 50  pounds  per  square 
inch,  valve  gear  cutting  off  at  ^  stroke,  piston  speed  varying  from  562  feet  for  the  smallest  up  to  666  for  the  largest,  size.  These  conditions  can  be  changed,  and 
by  increasing  one  or  all,  the  power  of  an  engine  is  increased  in  like  proportion. 


NOTES  ON  POWER  PLANT  DESIGN 


49 


HEWES   &   PHILLIPS   HEAVY   DUTY 
CROSS   COMPOUND   CORLISS   ENGINE  —  TANGYE  TYPE 


Dimensions  of 
Cylinder   ' 

Band  Wheels 

Horse-power  80  Lbs 
Initial  Pressure 
%  Cut-off 

Horse-power  go  Lbs 
Initial  Pressure 
%  Cut-off 

Horse-power  100  Lbs 
Initial  Pressure 
%  Cut-off 

Size  of  Quadrangle 
within  which  Engine 
including  Fly-wheel 
wilt  stand 

Length  of 
Crank-shaft 
from  Outside 
of  Main 
Bearings 

Ft.     Ins. 

Distance 
from  Center 
ofCrankshaf 
to  End  of 
Cylinder 

Ft.   Ins. 

Height  from 
Base-plate 
to  Center  of 
Crankshaft 

Ft.    Ins. 

Horse-power 
Constant 
Based  on 
Pound  M. 
E.  P.  i  Rev. 

Bore 
in  Inches 

Stroke 
in  Inches 

Diameter 
in  Feet 

Face 

in  Inches 

inbound 

Revs,  per 

Minute 

Horse- 
power 

Revs,  per 
Minute 

power 

Revs,  per 
Minute 

Horse- 
power 

Length 
Ft.    Ins. 

Width 

Ft.    Ins. 

10 

24 

6 

12 

4OOO 

125 

5° 

125 

55 

125 

62 

13       I 

5   n 

5->   3 
T5 

10       I 

I       II 

.0094 

12 

24 

7 

14 

500O 

25 

75 

I25 

84 

125 

93 

14     II 

6     9 

'  5     3 

IO    II 

I       II 

•0137 

12 

30 

8 

14 

6OOO 

20 

85 

20 

94 

I  2O 

104 

16    n 

6     9 

5     2}2 

12     II 

I        II 

.0171 

14 

30 

8 

18 

70OO 

2O 

"5 

2O 

125 

120 

,J37 

17      7 

7      7 

5    10^ 

•3        ! 

2          I 

.0230 

H 

36 

9 

18 

80OO 

10 

126 

IO 

M3 

no 

1  60 

19     7 

7      7 

5    10^ 

2          I 

.0276 

l6 

3° 

10 

2O 

9OOO 

20 

!5' 

2O 

170 

1  20 

190 

18     5 

8      8 

6     6 

•3     S 

2          3 

.0301 

16 

36 

10 

24 

IOOOO 

IO 

166 

IO 

190 

IIO 

213 

20     5 

8     8 

6     6 

1S     S 

2          3 

.0361 

16 

42 

12 

24 

10600 

00 

i77 

00 

200 

IOO 

226 

23     5 

8     8 

6     6 

'?     5 

2          3 

.0421 

18 

36 

12 

26 

I2OOO 

10 

210 

IO 

240 

IIO 

270 

21         6 

9     5 

8     3f'5 

15     6 

2       5 

.0457 

18 

42 

M 

28 

I40OO 

oo 

223 

OO 

255 

IOO 

287 

24     6 

9     5 

17     6 

2       5 

•°533 

20 

36 

12 

28 

140OO 

IO 

236 

IO 

270 

IIO 

305 

22      II 

i°     3 

8     8}4 

15    ii 

2          6 

.0564 

20 

42 

14 

3° 

I700O 

oo 

275 

IOO 

3i5 

IOO 

355 

24      II 

8     8^2 

17    ii 

2          6 

.0658 

20 

48 

16 

34 

I9OOO 

90 

284 

90 

325 

90 

365 

27      II 

10     3 

O         v/2 

19    u 

2          6 

•0753 

22 

42 

16 

36 

2IOOO 

IOO 

334 

IOO 

382 

IOO 

422 

26        2 

ii      i 

10     3 

18     2 

2       9 

.0797 

22 

48 

16 

38 

230OO 

90 

344 

90 

393 

90 

442 

28        2 

1  1      i 

10     3 

20        2 

2       9 

.0911 

22 

54 

16 

40 

25OOO 

So 

344 

So 

395 

80 

442 

30       2 

1  1      i 

i°     3 

22        2 

2       9 

.1024 

24 

42 

16 

40 

220OO 

IOO 

398 

IOO 

454 

IOO 

510 

28     8 

12       O 

u      3 

20       8 

2         II 

.0948 

24 

48 

16 

40 

2400O 

90 

408 

90 

468 

90 

527 

30     8 

12       O 

n      3 

22       8 

2        II 

.1084 

24 

54 

16 

44 

26OOO 

So 

410 

So 

468 

80 

526 

32     8 

12       0 

ii      3 

24     8 

2        II 

.1219 

26 

48 

16 

44 

3OOOO 

90 

480 

90 

548 

90 

617 

21      5 

2      .   9 

.1272 

26 

54 

18 

46 

320OO 

So 

480 

So 

549 

So 

618 

23     5 

2       9 

•  M3I 

26 

60 

18 

48 

34000 

75 

501 

75 

572 

75 

644 

25     5 

2       9 

.1591 

28 

48 

18 

48 

32000 

90 

563 

00 

645 

90 

726 

21      9 

2        IO 

•  '477 

28 

54 

18 

S2 

34000 

So 

563 

So 

645 

So 

727 

23     9 

2        IO 

.1662 

28 

60 

18 

54 

36000 

75 

587 

75 

672 

75 

757 

25     9 

2        IO 

.1846 

3° 
30 

48 

54 

18 
18 

56 
60 

3400O 
38000 

90 
80 

646 
646 

90 
80 

739 
740 

90 
So 

833 
834 

Shafts  as  desired 

22        2 
24        2 

2        IO 
2        10 

.1694 
.1906 

3° 

60 

18 

64 

40000 

75 

67? 

75 

77i 

75 

868 

26        2 

~2         IO 

.2118 

32 

48 

18 

58 

36000 

90 

736 

90 

841 

90 

948 

22        7 

2        IO 

.1928 

32 

54 

20 

61 

39000 

So 

734 

80 

841 

80 

947 

24      7 

2        IO 

.2166 

32 

60 

20 

66 

43000 

75 

766 

75 

877 

75 

988 

26     7 

2        IO 

.2410 

34 

54 

2O 

78 

60000 

So 

840 

So 

961 

So 

1083 

24    ii 

2        II 

•2477 

34 

60 

2O 

78 

60000 

75 

865 

75 

990 

75 

1115 

26    ir 

2        II 

.2720 

HORSE-POWER. —  In  the  computation  of  the  power  of  an  engine,  the  prime  factors  are  area  of  cylinder,  pressure  of  steam,  piston  speed,  and  point  at  which 
steam- is  cut  off.  Our  calculations  of  horse-power,  as  indicated  in  the  above  table,  are  based  upon  an  initial  steam  pressure  of  So,  90  and  100  pounds  per  square 
inch,  valve  gear  cutting  off  at  ^  stroke,  piston  speed  varying  from  500  feet  for  the  smallest  up  to  750  for  the  largest  size.  These  conditions  can  be  changed,  and 
by  increasing  one  or  all,  the  power  of  an  engine  is  increased  in  like  proportion. 


50 

CONDENSERS  AND  ACCESSORIES 

The  pressure  in  a  Condenser  is  always  higher  than  the  pressure  due  to  the  temperature  of  the 
steam.  The  difference  between  the  pressure  in  the  condenser  and  the  pressure  due  to  the  tem- 
perature of  the  steam,  gives  the  pressure  exerted  by  the  air  in  the  condenser.  The  air  comes 
in  part  from  the  feed  water  entering  the  boiler,  in  part  from  the  circulating  water,  in  the  case  of 
the  jet  condensers,  and  in  part  from  leakages  of  air  into  the  condensing  outfit.  Water  at  atmo- 
'spheric  conditions,  contains  from  2  to  5  per  cent  of  air  by  volume.  It  is  evident  that  the  leakage 
of  air  into  the  condensers  may  be  much  or  little  according  to  the  care  with  which  the  condenser  outfit 
was  installed. 

In  general,  a  wet  air  pump  handling  the  air  and  circulating  water  for  a  jet  condenser,  when 
running  at  a  piston  speed  of  SO  feet  per  minute,  should  displace  in  one  hour  from  three  to  three 
and  one-half  times'" "the s,  volume  of  circulating  water  used  per  hour.  The  wet  pump  for  a  surface 
condenser  haridrfng  both  condensed  steam  and  air,  should  displace  per  hour,  35  times  the  volume 
of  water  coming,  out  of  the  condenser-per  hour  as  condensate.  The  displacement  of  35  volumes 
is  generally  considered  about  right  for  a  vacuum  of  28  inches.  If  higher  vacuua  are  carried,  the 
figure  should  be  increased,  running  up  to  .perhaps  40. 

The  vacuum'iri  a  condenser  is  generally  measured  either  by  the  difference  in  level  of  mercury 
in  a  U-tube,  or  by  the  height  of  a  column  of  mercury  in  A  single  tube,  .this  height  being  measured 
above  the  surface  in  an  open  vessel  filled  with  mercury,  into  which  the  tube  extends.  The  differ- 
ence in  level  thus  read,  should  be  corrected  for  temperature,  if  the  percentage  of  the  perfect  vacuum 
is  to  be  obtained  by  comparison  with  a  barometric  reading  reduced  to  32  degrees  and  to  sea 
level.  This  correction  may  be  made  with  sufficient  accuracy  as  follows : — 

The  corrected  height  =  observed  height  (1  -  .0001  (t  -  32)  ). 

The  amount  of  cooling  water  required  for  the  condensation  of  a  pound  of  steam  is  commonly 
figured,  assuming  a  20  degree  increase  in  temperature  with  cold  cooling  water  at  70  degrees. 
The  heat  to  be  abstracted  from  each  pound  of  steam  which  has  passed  from  the  throttle  through 
the  condenser  may  be  found  by  subtracting  from  the  heat  brought  in  by  a  pound  of  boiler  steam, 
_the  heat  transformed  into  work  by  a  pound  of  this  steam  and  the  heat  of  the  liquid  condensate 
leaving  the  condenser. 

If  steam  is  bled  from  or  supplied  to  any  stages  or  receivers  of  a  turbine  or  engine,  the  amount 
of  heat  to  be  abstracted  by  the  condenser  may  be  calculated  by  the  same  process.  Proper  allow- 
ance of  course  must  be  made  for  the  steam  which  is  taken  out  before  reaching  the  condenser  and 
for  the  heat  in  any  steam  put  back  into  the  condenser  and  for  the  heat,  from  such  steam,  which  is 
transformed  into  work.  See  in  this  connection  the  discussion  of  the  bleeder  type  turbine  under 
the  general  heading  of  Cylinder  Efficiency  and  Rankine  Efficiency. 


SURFACE  CONDENSERS 

(1)  The  rate  of  heat  transmission  through  a  tube  is  nearly  directly  proportional  to  the  mean 
difference  in  temperature  between  the  liquid  on  the  inside  and  the  vapor  on  the  outside  of  the 
tube. 

(2)  The  rate  of  heat  transmission  is  proportional  to  the  square  root  of  the  velocity  of  the  vapor 
j>r     normal  to  the  line  of  tubes. 

(3)  The  rate  of  heat  transmission  is  proportional  to  the  cube  root  of  the  velocity  of  the  water 
in  the  tubes. 

An  article  by  Mr.  Orrok  in  "Power"  of  August  11,  1908,  gives  a  summary  of  the  various  tests 
made  on  the  transmission  of  heat  through  condenser  tubes.  A  smooth  curve  representing  the  mean 
of  the  various  experimental  results  was  drawn  by  Mr.  Orrok,  who  proposed  the  following  formula 


NOTES  ON   POWER  PLANT  DESIGN  51 

for  U  the  heat  transmission  per  sq.  it.  per  hour  per  degree  difference  of  temperature  inside  and 
outside  of  the  tube:  —  3  _ 

U  =  17  VV8     V.023  +  Vw 

Vs  =  velocity  of  steam  by  the  tube  generally  taken  as  625  ft.  p.  sec. 
Vw  =  velocity  of  water  in  tube  in  ft.  per  sec. 

Values  read  from  the  curve  give  — 

Vel.  of  water  in  tubes  U  Vel.  of  water  in  tubes 

in  ft.  per  second.  in  ft.  per  second.  U 

.5  350  4  675 

1  430  5  725 

2  545  6  775 

3  620  7  815 

Experiments  by  Mr.  E.  Josse  have  shown  much  higher  values  for  tubes  which  were  drained 
in  such  a  way  that  the  steam  condensed  on  the  upper  rows  did  not  trickle  down  over  the  lower  rows 
but  was  drained  to  the  shell,  thus  keeping  the  efficiency  of  the  lower  tubes  equal  to  that  of  the  upper 
tubes.  For  such  tubes  it  appeared  that  the  constant  17  in  the  preceding  formula  for  U  should 
be  made  20  or  25. 

Later  on  Mr.  Crrok  did  a  considerable  amount  of  experimental  work  on  this  subject  and  as 
a  result  of  his  more  recent  work  he  developed  the  following  formula  and  conclusions  which  are 
copied  from  Transactions  A.  S.  M.  E.,  1910. 

(a)  The  heat  transferred  from  condensing  steam  surrounding  a  metallic  tube  to  cold  water 
flowing  through  the  tube  is  proportional  to  the  seven-eighths  power  of  the  mean  temperature  dif- 
ference of  the  water  and  steam  temperatures.     This  is  equivalent  to  the  statement  that  the  co- 
efficient of  heat  transfer,  U,  is  inversely  proportional  to  the  eighth  root  of  the  mean  temperature 
difference. 

(b)  The  coefficient  of  heat  transmission,   U,  is  approximately  proportional  to  the  square 
root  of  the  velocity  of  the  cooling  water.  • 

(c)  The  coefficient  U  is  independent  of  the  vacuum  and  of  the  velocity  of  the  steam  among 
the  tubes  or  in  the  condenser  passages.     It  may  be  proportional  to  the  square  root  of  the  velocity 
normal  to  the  tubes,  but  in  all  common  cases  this  velocity  does  not  vary  more  than  a  tenth  part. 

(d)  The  effect  of  air  on  the  heat  transferred  is  very  marked  indeed,  particularly  at  high  vacuua, 
and  most  of  this  air  is  due  to  leakage  through  the  walls  and  joints  of  the  apparatus.    The  effect 
of  the  presence  of  air  in  reducing  the  value  of  U  is  as  follows: 


where  P8  is  the  partial  pressure  due  to  the  steam  and  Pt  is  the  total  steam  and  air  pressure. 

(e)  Taking  the  heat  transfer  of  the  copper  tube  as  1.00  under  similar  conditions  the  transfer 
for  other  materials  is  approximately  as  follows:  —  copper,  1.00,  Admirality  0.93,  aluminum  lined 
0.97,  Admiralty  oxidized  (black)  0.92,  aluminum-bronze  0.87,  cupro-nickel  0.80,  tin  0.79,  Admiralty 
lead-lined  0.79,  zinc  0.75,  Monel  metal  0.74,  Shelby  steel  0.63,  old  Admiralty  (badly  corroded) 
0.55,  Admiralty  vulcanized  inside  0.47,  glass  0.25,  Admiralty  vulcanized  both  sides  0.17.     This 
coefficient  (due  to  the  material  of  the  tube)  will  be  designated  by  /*.     Corrosion,  oxidation,  vul- 
canizing, pitting,  etc.,  have  also  a  marked  effect  in  reducing  the  transfer.     This  reduction,  best 
shown  by  the  Admiralty  tube  which  gave  pi  =  0.55,  may  reduce  the  transfer  at  least  50  per  cent. 

(f)  The  foregoing  conclusions  may  be  expressed  mathematically  as  follows: 


52  NOTES  ON  POWER  PLANT  DESIGN 

where  C  =  the  cleanliness  coefficient  varying  from  1.00  to  0.5 
n  =  material  coefficient  varying  from  1.00  to  0.17 

p 

<p  =  the  steam  richness  ratio-^— varying  from  1.00  to  0 

"  t 

Vw  =  the  water  velocity  in  ft.  per  sec. 
0  =  the  mean  temperature  difference. 
K  =  a  constant,  probably  about  630. 

The  effect  of  the  length  of  tube,  or  rather  length  of  water  travel,  has  not  been  considered  and  the 
design  of  the  condenser  must  be  such  that  there  is  a  free  steam  passage  to  every  tube. 

(g)  This  expression  for  U  is  cumbersome  to  use  and  for  modern  turbine  condenser  work  cer- 
tain conditions  may  be  taken  as  well  settled.  The  guaranteed  vacuum  U  usually  28  ins.  The 
entrance  circulating  water  is  usually  70  deg.  and  a  20-deg.  temperature  rise  is  considered  economical. 
Under  these  conditions  0  =18.3  and  0*  =  1.44.  0  calculated  on  the  geometrical  curve  is  18.2. 
For  these  cases  it  will  be  nearly  as  accurate  and  much  simpler  to  calculate  0  by  the  logarithmic 

£»O    /"i 

method,  neglecting  0  in  the  denominator  and  using  435  or  ^~rr  for  Kl.     The  expression  will  then  be 


(h)  The  above  equation  agrees  well  with  the  results  of  a  number  of  tests  on  full  sized  condensers 
under  varying  conditions.  There  appears  to  have  been  no  attempt  to  determine  the  amount  of 
air  handled  by  the  air  pump  in  these  cases,  but  the  amounts  of  air  indicated  by  the  formula  are 
such  as  agree  with  the  pressures  and  temperatures  taken. 

/p  \2 

Later  work  by  Mr.  Orrok,  led  him  to  suggest  that  the  term  <^2  =  I  -~  I    be  substituted  for  <p*  in 

\rt/ 

the  expression  for  U. 

The  value  525  has  been  commonly  used  as  the  B.  T.  U.  per  sq.  ft.  per  hour  per  degree  difference 
in  temperature. 

The  modern  surface  condenser  used  for  steam  turbine  work  is  designed  to  maintain  a  tempera- 
ture in  the  hot  well  as  near  as  possible  to  the  temperature  corresponding  to  the  vacuum. 

The  mean  temperature  difference  is  often  taken  as  ts  -  —where  ts  =  the  temperature  of 

a 

the  steam;  th  =  the  temperature  of  the  hot  condensing  water  and  tc  the  temperature  of  the  cold 
condensing  water. 

The  true  mean  temperature  difference  0  =  h  ~  c 

loge  - 


~JL 

If  t  =  any  momentary  temperature;  W  the  weight  of  injection  water  per  hour;  Fthe  B.  T.  U.  per 
hour  per  square  foot  of  surface  per  degree  difference  in  temperature,  and  A  the  condensing  sur- 
face in  square  feet. 

u  dA  (ts  -  g  -  w  dt  w  A ,        w 

A  -  -  W      s  ~    h. 

J    f  t        ~   TT     IOee  ~t          ~T 

u  tk  °  ~  ^-   u        ts  ~ te 

-  Q  whence  0  =  ^—± 
ts  — 


NOTES  ON  POWER  PLANT  DESIGN  53 

Illustration  of  method  of  calculating  surface  needed  in  a  condenser.  Condenser  to  handle 
15,000  Ibs.  steam  per  hour,  the  steam  containing  6  per  cent  of  moisture:  Vacuun  28";  Barometer 
30";  cold  water  70°;  hot  water  90°;  condensate  5  degrees  below  temperature  of  steam.  The  dif- 
ference between  the  pressure  in  the  condenser  and  that  corresponding  to  the  temperature  of  the 
steam  is  J4"  of  mercury  in  this  case.  Velocity  of  injection  water  through  tubes  7  feet  per  second. 
Required  total  surface  qn  —  98  _  tt 

U  =  435  x  C  x  <P*  X  A«   Ww;  using  .75  for  C  and  -  *  =  .875  for 

.  oU 

<t>\  .7  for  fj.  this  becomes  435  x  .75  x  .76  X  .7  x  2.64  =  458.  0  =  18.3  see  item  (g)  in  quotation 
from  Orrok's  paper.  458  X  18.3  =  8391.  B.  T.  U.  per  hour  per  square  foot  of  surface. 

The  heat  to  be  abstracted  is  15000  (.94  r  +  q  -  59.8)  =  13,843,500.6.  T.  U.;  r  and  q  being  taken 
at  1.75  X  .491  =  .86  Ibs.  absolute.  13,843,500  -=-  8,391  =  1650  square  feet,  the  surface  needed. 

In  general  from  1.2  to  2.5  square  feet  of  surface  are  allowed  per  K.  W.  for  large  units,  the 
amount  of  surface  increasing  to  4  square  feet  per  K.  W.  for  small  units. 

WESTINGHOUSE-LEBLANC   SURFACE  CONDENSERS 

An  Abstract  from  the  May,  1914,  Bulletin  of  the  Westinghouse  Machine  Company. 

The  principles  governing  the  design  of  jet  condensers,  in  which  there  is  an  intimate  mixture 
of  the  steam  and  circulating  water,  are  simple  and  well  known,  but  in  surface  condensers  where 
the  heat  of  the  exhaust  steam  is  transmitted  to  the  cooling  water  through  metal  tubes,  the  problem 
is  more  complex. 

In  designing  a  surface  condenser,  the  amount  of  steam  to  be  condensed,  the  vacuum  desired 
and  the  temperature  and  amount  of  circulating  water  available,  are  determinate.  Not  only  do 
these  bear  a  close  inter-relation,  but  they  have  a  marked  effect  on  the  other  details  of  design. 

Knowing  the  total  number  of  heat  units  to  be  taken  from  the  steam  and  the  amount  of  heat 
(depending  upon  its  temperature  rise)  which  each  pound  of  circulating  water  will  absorb,  the 
amount  of  surface  necessary  to  transmit  the  heat  may  be  determined.  This  calculation  will  involve 
a  consideration  of  the  following:  (1)  The  velocity  of  the  circulating  water,  (2)  the  material  used 
for  tubes  and  their  arrangement,  (3)  the  mean  temperature  difference  between  the  steam  and  water, 
and  (4)  the  amount  of  air  on  the  steam  side  of  the  tubes. 

(1)  Careful  investigations  show  that  the  heat  transfer  varies  approximately  as  the  square 
root  of  the  velocity  of  the  cooling  water  in  the  condenser  tubes.     Therefore,  the  higher  the  velocity 
of  the  water,  the  greater  the  heat  transfer,  but  due  account  must  be  taken  of  the  greater  power 
required  for  high  velocities.     In  general,  the  velocity  should  be  such  as  will  result  in  tumultous 
rather  than  smooth  and  stratified  flow,  thereby  bringing  each  particle  of  water  into  contact  with 
the  surface  of  the  tubes. 

(2)  Different  materials  may  be  used  for  the  tubes  depending  on  the  nature  of  the  circulating 
water.     Copper  alloys  are  more  generally  used  than  other  materials.     In  the  arrangement  of  the 
tubes,  it  is  quite  important  that  restricted  passages  be  avoided  so  the  steam  may  pass  freely  from 
one  side  of  the  condenser  to  the  other,  thereby  avoiding  undue  pressure  drop  or  loss  in  vacuum. 

(3)  The  amount  of  heat  which  will  pass  through  the  tube  wall  is  proportional  to  the  mean 
temperature  difference  which  is  determined  by  the  expression  — 

th  —  tc 


ts- 
Loge     ^— ^ 

J#— 

when  ts  is  the  temperature  of  the  steam,  tc  and  th  are  the  temperatures  of  the  intake  and  discharge 
water  respectively.  For  ordinary  conditions,  it  is  sufficiently  accurate  to  use  the  arithmetical 
mean  as  calculated  from  the  expression  — 

ts n 


54 


NOTES  ON  POWER  PLANT  DESIGN 


(4)  The  most  important  factor  affecting  heat  transfer  is  the  presence  of  air  on  the  steam 
side  of  the  tubes.  Some  of  this  air  is  carried  into  the  condenser  with  the  ?team  but  this  quantity 
is  so  small  as  to  be  almost  negligible.  The  greater  portion  enters  by  leakage  at  valves  and  joints 
and  by  infiltration  through  the  cast  iron  connections  and  the  condenser  shell. 

Under  the  low  pressure  conditions  existing  in  a  condenser  the  density  of  air  is  greater  than 
steam.  So  if  any  appreciable  amount  of  air  is  present  it  will  collect  in  the  bottom  of  the  condenser 
and  "drown"  or  "blanket"  the  lower  tubes,  thereby  preventing  the  steam  from  coming  into  proper 
contact  with  them.  It  is  therefore  necessary,  if  the  best  results  are  to  be  obtained,  that  the  air 
be  removed  continuously  and  completely  from  the  steam  space. 

Any  air  in  the  steam  space  will  have  a  finite  pressure  and  the  total  pressure  would  be  due  partly 
to  steam  and  partly  to  air  pressure.  As  may  be  seen  by  reference  to  any  "Steam  Tables"  the  vapor 
at  a  given  pressure  has  a  definite  temperature  —  the  lower  the  pressure,  the  lower  the  temperature. 
It  is  obvious  that  if  the  air  pressure  is  high,  the  steam  pressure  is  low  with  a  correspondingly  low 
temperature. 

A  concrete  case  in  tabular  form  will  make  this  relationship  clear.  In  some  condensers  the 
difference  in  temperature  between  the  upper  and  lower  portions  of  the  steam  space  may  be  10 
or  15°  F.,  while  in  others  not  more  than  1  or  2°  F.  Assuming  the  total  absolute  pressure  in  the 
top  of  the  condenser  to  be  0.975  pounds  per  square  inch,  (vacuum  28.01")  and  temperatures  of 
85,  90  95,  and  100°  F.  in  the  lower  portion  of  the  steam  space  with  no  pressure  drop  in  passing 
through  the  condenser,  the  resulting  air  and  steam  pressures  are  as  follows: 

Temperatures  in  bottom  of  Condenser 

Total  pressure  Ibs.  per  square  inch 

Steam  pressure  corresponding  to  assumed  temperature 


85° 
0.975 
0.594 


90° 
0.975 
0.696 


95°          100° 
0.975        0.975 
0.813         0.946 


Air  pressure 


0.381         0.279         0.162         0.029 


From  this  tabulation  it  will  be  seen  that  with  a  vacuum  of  28.01"  if  the  air  pressure  is  0.381 
the  maximum  temperature  of  the  steam  in  the  lower  portion  of  the  condenser  is  85°  F.,  when  0.279 


Cross-section  showing  arrangement  of  Tubes 

pounds  90°  F.,  etc.,  showing  very  clearly  how  the  pressure  of  air  lowers  the  steam  temperature 
and  consequently,  the  "heat  head"  between  the  steam  and  cooling  water.  It  is  only  by  remov- 
ing the  air  to  the  lowest  possible  amount,  that  the  maximum  "heat  head"  and  consequent  rate  of 
heat  transfer  may  be  secured. 

Another  loss  arising  from  the  presence  of  air  is  due  to  the  fact  that  the  temperature  of  the  con- 
densate  must  be  raised  a  greater  amount  the  higher  the  air  pressure. 

The  condenser  shell  which  is  usually  circular  in  form,  is  made  of  exceedingly  close  grained  cast 
rion,  the  location  of  the  water  and  steam  connections  being  determined  by  local  conditions. 


In  the  smaller  sizes,  say  up  to  10,000  square  feet,  the  shell  and  nest  of  tubes  are  concentric, 
as  shown  at  the  left  in  the  cross  section  on  the  page  preceeding  this. 

The  pitch  and  arrangement  of  the  tubes  is  such  that  the  pressure  drop  of  the  steam  in  passing 
from  one  side  to  the  other  is  negligible. 

In  large  condensers,  owing  to  the  distance  the  steam  has  to  travel,  special  care  is  necessary 
to  prevent  undue  resistance  and  consequent  loss  in  vacuum.  At  the  right  in  this  same  cut  is  a 
sectional  view  of  a  large  condenser.  The  nest  of  tubes  is  placed  non-concentric  to  ihe  condenser 
shell,  so  that  steam  enters  around  the  whole  periphery.  Such  an  arrangement  practically  doubles 
the  area  for  the  admission  of  the  steam,  and  so  results  in  a  velocity  only  one  half  of  that  in  other 
types.  The  air  offtake  consists  of  two  parallel  plates  extending  the  entire  length  of  the  condenser, 
thus  reducing  the  distance  the  air  has  to  travel  to  one  half  of  that  in  the  older  types  of  condensers. 

As  all  condensate  must  fall  through  the  surrounding  envelope  of  live  steam,  its  temperature 
will  be  practically  the  same  as  that  of  the  entering  steam. 

The  advantages  of  this  arrangement  may  be  summarized  as  follows: 

First:  Non-concentric  arrangement  of  tubes  gives  a  steam  velocity  only  one  half  of  that  in 
the  ordinary  type.  , 

Second:  Radial  flow  reduces  the  length  of  the  steam  path  through  the  tubes  to  one  half  of 
that  ordinarily  existing. 

Third:    Highest  possible  temperature  of  condensate. 

How  well  this  design  fulfills  its  purpose,  is  shown  by  numerous  tests  made  on  large  condensers 
whore  the  temperature  of  the  condensate  was  found  to  be  within  one  or  two  degrees  of  that  of  the 
incoming  steam,  and  the  difference  in  pressure  between  the  air  pump  offtake  and  the  top  of  the 
condenser  not  more  than  0.1"  mercury. 

The  condenser  tubes  used  are  of  different  standard  materials  depending  on  the  character  of 
the  cooling  water.  Muntz  metal  is  generally  used  for  both  the  tubes  and  tube  sheets.  To  pre- 
vent sagging,  long  tubes  are  supported  between  the  ends,  the  number  of  supports  depending  on 
the  length.  The  method  of  packing  each  end  of  the  tubes  is  shown  by  the  cut. 
C  is  a  fibre  packing  held  in  place  and  expanded  by  bronze  nut  D.  The 
fibre  expands  when  wet  and  makes  a  tight  joint  which  is,  however,  easily 
removable  in  case  it  is  necessary  to  replace  a  tube. 

In  view  of  the  importance  of  completely  scavenging  the  condenser 
of  air,  it  is  obvious  that  the  air  pump  must  be  capable  of  handling  it 
at  extremely  low  pressures  from  which  it  must  be  compressed  to  that 
of  the  atmosphere.  The.  fact  that  the  volumetric  efficiency  of  the  West- 
inghouse-Leblanc  Air  Pump  increases  as  the  density  of  the  air  which  it 
is  handling  decreases,  gives  it  a  singular  suitability  for  such  service. 

The  ideal  air  pump  would  be  one  in  which  the  volumetric  efficiency 
increased  at  such  a  rate  that  constant  weight  of  air  wrould  be  handled. 
While  this  is  clearly  impossible,  careful  tests  show  that  the  Westinghouse- 
Leblanc  pump  more  nearly  approaches  the  ideal  than  any  other.  Its 
volumetric  efficiency  increases  rapidly,  even  Rafter  the  reciprocating  pump-(due.  to  limitations  of 
clearance)  has  ceased  to  be  of  any  value  whatever. 

The  mechanical  simplicity  and  ruggedness  of  the  air  pump  makes  it  an  ideal  adjunct  to  the 
surface  condenser.  The  only  moving  part  of  the  pump  is  the  rotor  or  impeller,  marked  !J,  which 
is  a  solid  bronze  casting  practically  indestructible  under  ordinary  water  conditions. 

By  referring  to  the  figure  on  page  57  which  shows  an  air  and  condensate  pump  mounted  $u  the 
same  shaft,  it  will  be  seen  that  air  enters  the  pump  through  the  pipe  C.  To  start  the  pump  in' oper- 
ation, high  pressure  steam  is  turned  into  the  connection  D.  The  cone  forms  the  annular  nozzle 
of  a  steam  ejector,  so  that  on  opening  the  valve  in  the  steam  line  a  vacuum  is  created  in  the  body 
of  the  air  pump.  The  chamber  E  being  piped  up  to  a  source  of  water  supply,  is  immediately  filled 
on  account  of  the  vacuum  created  by  the  steam  ejector.  Water  then  flo\vs  through  the  distributing 
nozzle  F  and  is  projected  in  Ia3^ers  through  the  combining  passage  G  into  the  diffuser  H.  Between 
the  successive  layers  of  water,  layers  of  air  are  imprisoned,  these  layers  of  water  (on  account  of  the 
high  peripheral  speed  of  the  turbine  wheel  which  throws  them  off)  have  a  velocity. sufficient  to 
enable  them  to  overcome  the  pressure  of  the  atmosphere  and  force  their  way  out  of  the  pump  in 


56 


NOTES  ON  POWER  PLANT  DESIGN 

c 


TURBINE 


SECTION  AA 

Cross-Section  of  Air  and  Condensate  Pump 

which  a  high  vacuum  exists.     The  layers  of  water  act  like  a  succession  of  water  pistons  with  large 
volumes  of  air  between  them. 

Cold  water  is  used  in  the  air  pump;  the  specific  heat  of  air  is  low  and  its  weight  small  com- 
pared with  that  of  the  water,  and  there- 
fore the  air  is  immediately  cooled  on 
entering  the  pump  to  the  lowest  possible 
temperature. 

The  water  discharged  from  the  air 
pump  is  not  appreciably  heated,  and  may 
therefore,  be  returned  to  the  cold  well. 
It  must  be  remembered,  however,  that  in 
reality  a  mixture  of  water  and  air  is  dis- 
charged, so  that  in  discharging  to  the  cold 
well,  proper  provision  must  be  made  for 
•separating  the  air  from  the  water. 

The  advantage  of  such  a  pump  may 
easily  be  seen.  There  are  no  close  clear- 
ances or  rubbing  surfaces  requiring  con- 
stant attention  —  no  reciprocating  parts 
with  their  attendant  packing  troubles. 

It  is  obvious  that  the  air  handling 
capacity  of  this  pump,  owing  to  the  use 
of  water  pistons,  is  much  greater  than  the 
ordinary  ejector  arrangement  where  the 
air  -ls  g}mpiy  carried  along  by  friction.  It 
is  to  be  noticed  that  the  water  is  dis- 
charged through  a  comparatively  large 
opening  through  which  small  debris  may 
pass  without  clanger  of  clogging.  Some 
hydraulic  pumps  of  this  general  type,  have 
a  very  narrow  discharge  opening  extend- 
ing around  the  entire  circumference,  and 
as  a  result  much  trouble  is  experienced 
from  foreign  matter,  and  it  is  often  nec- 
essary to  use  perfectly  clean  water  co 
insure  satisfactory  operation. 

The  pump  that  takes  the  condensed 
steam  from  the  condenser  is  usually  called 
the  condensate  pump.  Although  it  is  in 
point  of  size,  probably  the  smallest  of 


—Typical  Surface  Condenser  Installation 


NOTES  ON  POWER  PLANT  DESIGN  57 

the  condenser  appurtenances,  its  function  is  just  as  important  as  that  of  the  others.  It  draws 
the  water  from  the  high  vacuum  within  the  condenser  and  discharges  it  to  the  desired  place, — 
usually  the  feed  water  tank. 

This  pump  is  of  the  single  stage  centrifugal  type,  usually  driven  by  its  own  turbine.  If  desired, 
the  condensate  pump  may  be  placed  on  the  end  of  the  air  pump  shaft. 

The  accompanying  cut  shows  how  readily  the  larger  condensers  may  be  placed  directly  beneath 
the  turbine.  In  this  particular  case,  the  condensate  and  air  pump  are  mounted  on  one  shaft 
which  is  turbine  driven.  The  circulating  pump  is  also  turbine  driven. 

The  condensers  described,  have  been  developed  for  the  production  of  high  vacuua  and  are 
intended  primarily  for  use  with  steam  turbines  where  such  vacuua  may  be  effectively  utilized. 

They  have  been  built  in  sizes  ranging  from  one  thousand  to  fifty  thousand  square  feet  in  a  single 
shell,  the  latter  probably  being  the  largest  ever  constructed. 


CONDENSER  TESTS 

The  following  extracts  from  tests  made  on  Westinghouse  Surface  Condensers  after  installation 
show  in  a  striking  manner  How  completely  the  air  is  removed  from  the  steam  space,  and  how  closely 
the  temperature  of  the  condensate  corresponds  to  that  of  the  steam  entering  the  condenser. 

PUBLIC  SERVICE  ELECTRIC  CO.  Size  —  20,000  Sq.  Ft. 

Marion,  N.  J.  Connected  to  9,000  K.  W. 

High  Pressure  Turbine. 

Date,  Oct.  26th,  1913.  3  P.  M.      4  P.  M. 

Load  in  K.  W.  on  Turbine      ......................      9,000  6,000 

Barometer     ...........................     30.16  30.14 

Vacuum  at  top  of  Condenser  by  Mercury  Column  ................     28.96  29.05 

Temperature  at  Top  of  Condenser  °F  ....................     83  79 

Temperature  Condensate  Pump  Water  °F  ...................     82  79 

Vacuum  at  Air  Pipe  Connection  .....................     29.08  29.12 

Temperature  Injection  Water  Inlet  °F  ..............      ......     66.5  68 

Temperature  Injection  Water  Discharge  °F  ..................     78  76 

CAMBRIDGE  ELECTRIC  LIGHT  CO.  Size  —  5,000  Sq.  Ft. 

Cambridge,  Mass.  Connected  to  1,500  K.  W. 

Low  Pressure  Turbine. 

Date,  May  28th,  1913.  9  A.  M.        11  A.  M.   1  P.  Ml 

Load  in  K.  W.  on  Turbine      .......      ...........  1,225  1,275  1,250 

Barometer    .....  ...............  29.88  29.88  29.88 

Vacuum  at  Top  of  Condenser  by  Mercury  Column      ...........  28.56  28.55  28.55 

Temperature  at  Top  of  Condenser  °F  ..........      ......  84  85.5  85 

Temperature  Condensate  Pump  Water  °F  ...............  82  "82.5  82.5 

Vacuum  at  Air  Pipe  Connection  ..................  28.7  28.66  28.65 

Temperature  Injection  Water,  Inlet  °F  ...............  59  59  59 

Temperature  Injection  Water,  Discharge  °F  ..............  77  11%  11 


DETROIT  UNITED  RAILWAYS  CO.  Size  —  4,000  Sq.  Ft. 

Monroe,  Michigan.  Connected  to  2,000  K.  W. 

High  Pressure  Turbine. 

Date,  August  10th,  1913.  9A.M.      9.30A.M.    10A.M 

Load  in  K.  W.  on  Turbine      ..................  2100  1800  2100 

Barometer     .......................  29.25  29.25  29.25 

Vacuum  at  Top  of  Condenser  by  Mercury  Column      ...........  27.20  27.25  27.20 

Temperature  at  Top  of  Condenser  °F  ................  102  102  103 

Temperature  Condensate  Pump  Water  °F  ...............  100  100  101 

Vacuum  at  Air  Pipe  Connection  .................  27.20  2725  27.25 

Temperature  Injection  Water  Inlet  °F  .....  ..........  84  84  84 

Temperature  Injection  Water  Discharge      ..............  101  100  101 


58 


NOTES  ON  POWER  PLANT  DESIGN 

Air  Pump  Di-sch. 

r 


EZIt 


Circ.  Wafer  In/ei- 


Turbine   Steam 
Turbine   Exhaust" 


Area  s<?  ft.      /OOO     2OOO    3OOO  4-OOO    SOOO    Condensatc  dip 


*       G 


H 


M 


Mef  cfio. 


IS'  -O 


19  -/ 


-J-- 


/s-s 


6-/0/ 


8'~3 


2'-  6 


te 


18" 


6'-»i' 


S'-S 


/O 


7'-o 


is 


36 


26'-3 


ft      7  * 
8      7/6 


10 


3-9" 


2'  -4-" 


4--SJ 


B-7 


4-2 


9-°$' 


2-ff 


27-O 


8-9% 


6  -8 


Q'-IO" 


4-'-  8 


2  '-  7 


4-8' 


j-o 


3-  1/? 


20* 


14- 


/o'-o* 


'-to 


2  '-10 


4-8 


ff  '-// 


3'-3 


*      e 


Air  Pump  dia 


*      h 


Priming  of/a. 


C/rc.  Inlet  dia 


C/rc.  Disch.  dio. 


Turb.  •St.  efia 


Turb  Ex.  d/a. 


y 


9'-6J 


2-4- 


16 


7' 


4-' 


3s 


3-0 


2-8 


12 


4-7* 


IB 


12 


ta 


4k 


12-  I 


3-2 


6' 


28 


2-2 


14-' 


/a 


2 


13 


3- 


11$ 


20 


/* 


2-6 


13 


IDs 


+-' 


20 


"4 


18 


18" 


2? 


>* 


Noi-e:- 

lr>  the   IOOO   etna/  SOOO  sp.  f+.    s/zrs  no  reducing    year  is.  u-secj, 
the   turbine  couples   direct    to  pumpj. 

*    Where    no  reducing    gear-  i-s   used   these    connections   are  on 
of  her  side    of   condenser  from  that"  shown   in   diagram. 

$    In  two  -smallest   -sizes    priming   connect/on   opens   downward. 


NOTES  ON  POWER  PLANT  DESIGN 

THE  WHEELER  CONDENSER  AND  ENGINEERING   COMPANY 
WHEELER  ADMIRALTY  SURFACE  CONDENSER 


Sq.  Ft. 

of 

Surface 
463 
606 
751 
1042 
1109 
1379 
1778 
2051 
2223 
2757 
3446 
4135 
4679 
5069 
5849 
6733 
7714 
8307 


A 

7'-0" 
8'-0" 
8'-0" 
8'-0" 
8'-0" 
8'-0" 
8'-0" 
8'-0" 

lO'-O" 
8'-0" 

lO'-O" 


B 

8'-3" 
9'-4" 
9'-7" 
9'-8" 
9'-5" 


10'  -8" 


17'  0" 


c 

3'-0" 

3'-0" 
3'-5" 
3'-8" 
4'-0" 
4'-4" 
4'-8" 
4'-6" 
5'-4" 
5'-4" 
5'-4" 
5'-6" 
5'-6" 
5'-6" 
5'-8" 
6'-6" 


D 


E 

21K" 
22^" 


22ys" 
23^" 


2-6 

2'-6" 

2'-6" 

2'-7" 

3'-0" 

3'-0" 


22H" 
2'-l" 

2'W 


3-2" 
3'-4" 
3'-2" 


Diameter 

of 

Tube 

K" 
W 

*A" 
5" 


K" 

K" 


Weight 

Lbs. 

3400 

4500 

5200 

6600 

7200 

9200 

11100 

12900 

14000 

16200 

19600 

23000 

26500 

28300 

31800 

36900 

44200 

46700 


60 


NOTES  ON  POWER  PLANT  DESIGN 


WESTINGHOUSE  LE  BLANC  JET  CONDENSERS 

SIZES 


I  Grou 


Dia.  Openings 

Szc 

A 

2 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

fe5. 

16 

17  18 

19 

20 

21 

1 

3^41/2 

6ffX>3/4 

30 

333/g 

261/2 

163/4 

15i/g 

10 

91/2 

25V; 

223/8 

355/8 

2 

6/  -1  1/4 

135/g 

22     5 

3 

6 

5 

2 

3'  -4  1/2 

6"  -6  3/4 

31  M. 

333/8 

26V2 

163/4 

151/g 

10 

9i/2 

251/g 

223/8 

355/8 

2 

6*  -1  1/4 

135/8 

22     5 

3 

6 

5 

4 

3'  -ioyz 

7    -1% 

33 

34 

273/4 

18 

151/2 

10 

91/2 

25  3/ 

231/g 

3'  -2% 

28i/2 

6'  -6% 

14V4 

28     6 

3% 

7 

5 

5 

3'  -101/2 

7    -l7/g 

351/g 

34 

273/4 

18 

15i/2 

10 

91/2 

253/4 

231/g 

3'  -2% 

28i/7 

6'  -6% 

141/4 

28     6 

•i 

7 

5 

7 

4'  -4  1/2 

8    -51/2 

3"-3 

35« 

27i/8 

20 

1734 

10 

101/2 

301/4 

25 

3'  -57, 

313/P 

7'  -10 

151/4 

30     7 

4 

9 

6 

8 

4'  -4  1/2 

8   -51/2 

3  "-7 

35  « 

271/g 

20 

173/4 

10 

101/2 

301/4 

25 

3'  -5% 

313/t 

7'  -10 

151/4 

30     7 

5 

9 

0 

10 

5'-0 

8   -8»/4 

3"-10V2 

35  ft 

27i/8 

20 

181/g 

10 

101/2 

301/4 

251/4 

3'  -95/g 

35 

7'  -103/4 

15'/4 

36     9 

6 

12 

G 

11 

5'-0 

8   -8i/4 

4"-OV2 

35  H 

271/g 

20 

181/g 

10 

IQi/j 

301/4 

251/4 

3'  -9  5/g 

35 

7'-103/, 

15V, 

36     9 

6 

\'i 

0 

13 

5  '-7  1/2 

9   -10% 

4"-8 

3"-7% 

34yg 

21 

19 

10 

11  3/ 

353/4 

285/8 

4'-13/g 

3  "-3 

8'  -11% 

20V. 

42  12 

6 

14 

6 

14 

5  '-7  1/2 

9    -10% 

5"-0 

3"-7% 

34y8 

21 

19 

10 

113/4 

353/4 

285/g 

4'  -13/g 

3  "-3 

8'  -1  1  % 

201/4 

42  12 

7 

14 

6 

1C, 

6  '-7  1/2 

10    -113/g 

5"-63/4 

3"-10tJ 

3"-lA 

24 

193/4 

9% 

14 

3"-7 

295/g 

4  '-8  1/2 

3"-7i/2 

9'  -113/g 

221/2 

48  14 

8 

If 

10 

17 

6'  -7  1/2 

10   -11% 

6"-0 

3"-10H 

3"-l& 

24 

193/4 

9% 

14 

3  "-7 

295/g 

4'  -8  1/2 

3"-7V2 

9'  -11  3/g 

221/2 

48  14 

9 

16 

10 

18 

7"-5i/2 

13  "-5  1/2 

6"-4i/2 

4  "-6  if 

3"-8A 

3"-10i/4 

18% 

9% 

14 

4"-3V4 

29i/2 

5"-l  1/2 

4"-2 

12"-2V2 

293/4 

54  18 

9 

20 

10 

19 

7"-5«/2 

13"-5V2 

6"-8V2 

4"-6tf 

3"-8A 

3"-10i/4 

18% 

9% 

14 

4"-3V4 

29V2 

5"-l% 

4  "-2 

12"-2i/2 

29  3/< 

54  18 

9 

20 

10 

NOTES  ON  POWER  PLANT  DESIGN 


61 


WESTINGHOUSE  LEBLANC  JET  CONDENSERS 

CAPACITIES 

TURBINE  DRIVEN 

Based  on  5°  Terminal  Difference. 


Con- 
denser 

Circulating 
Wrt-r 

28"  VACUUM 

lumber 

Lbs.per  lir. 

35°  F. 

40°  r. 

45°  F. 

50°  F. 

50°  F. 

55°  F. 

60°  F. 

70°  F. 

75°  F. 

80°  F. 

1 

235,000 

17200 

15750 

144CO 

1CCCO 

11575 

10150 

8750 

7300 

5950 

4500 

2 

320,000 

208CO 

19200 

174CO 

15700 

14000 

12250 

10500 

8800 

7200 

5450 

4 

350,000 

22750 

20750 

19000 

17100 

15880 

13400 

11600 

9550 

7800 

5950 

5 

403,000 

26000 

23800 

21700 

19600 

17500 

15325 

13200 

11050 

9025 

6820 

7 

600,000 

39000 

•  ?5750 

32750 

290CO 

26400 

23000 

19750 

16600 

13400 

10250 

8 

750,  CCO 

4SOOO 

44750 

40750 

37000 

32750 

2COOO 

24800 

20500 

16750 

12850 

10 

825,000 

53500 

49000 

44750 

40400 

34750 

31800 

27300 

22750 

18400 

14100 

It 

940,000 

610CO 

55800 

51000 

46000 

41000 

36000 

31000 

25750 

21000 

16000 

13 

1,200,OCO 

775CO 

71000 

65200 

58600 

52750 

46000 

39250 

33250 

26600 

20500 

14 

1,550,OCO 

100600 

92500 

84000 

75750 

57750 

59300 

51150 

42750 

34650 

26400 

16 

1,850,C(0 

120500 

11000 

100500 

910CO 

81000 

71000 

61000 

51000 

41500 

31600 

17 

2,200.  OCO 

143000 

1310(0 

11  9000 

107500 

96000 

84000 

72500 

60800 

49250 

37500 

18 

2,620,000 

170000 

1560CO 

142000 

128000 

114500 

100320 

86300 

72250 

58600 

44500 

19 

3,000,000 

194700 

178500 

1620CO 

147000 

131000 

1150CO 

99040 

82000 

67000 

51100 

20 

4,000,000 

26COOO 

238000 

217^00 

196000 

174600 

153200 

132000 

110300 

89400 

68100 

21 

5,000,000 

325CCO 

298000 

271500 

245000 

218500 

191500 

165300 

138000 

111600 

85200 

22 

0,000,000 

289CCO 

257000 

?  25000 

293000 

2620CO 

2300CO 

198000 

166000 

134000 

102000 

23 

7,000  000 

4550CO 

416000 

c.  80000 

342000 

305000 

268000 

231000 

194000 

156000 

119000 

24 

9,000,000 

5800GO 

530COO 

485000 

447000 

390000 

344000 

295000 

248000 

212000 

153000 

25 

11,000,000 

710000 

6500CO 

590000 

545000 

475000 

420000 

360000 

304000 

258000 

187000 

26 

13,000,000 

840000 

77COCO 

70(X)00 

645COO 

560000 

495000 

425000 

360000 

305000 

220000 

The  figures  given  aro  based  on  the  assumption  that  the  temperature  of  the  mixture  of  water  and  steam  is  5  degrees 
less  than  the  theoretical  temperature  corresponding  to  the  vacuum. 
The  following  conditions  are  assumed: 

1.  That  condenser  pumps  are  steam  driven. 

2.  Temperature  of  injection  water 70  Degress  F. 

3.  Level  of  watsr  supply  balow  top  of  condenser  daes  not  exceed 13  Feet 

4.  Discharge  water  is  to  be  elevated  above  base  of  condenser,  not  to  exceed  (including 

pipe  friction) 4  Feet 

5.  Suction  pipe  is  to  be  so  arranged  that  friction  head  will  not  exceed  the  equivalent  of.       2  Feet 

6.  Vacuum  at  rated  load,  referred  to  a  barometric  pressure  at  30  inches       ...     28  Inches 


C2 


NOTES  ON   POWER  PLANT   DESIGN 


THE  WHEELER  CONDENSER  AND   ENGINEERING   COMPANY 
DIMENSIONS   OF  WHEELER-EDWARDS  AIR  PUMP 


4x10x8 

5x12x10 

6-14-10 

7-16-10 

8-18-12 

8-20-12 

9-24-12 

10-26-12 

12-30-14 


Capacity 
in  Ibs.  per 
hour 

28"  Vac. 


4500 
7500 
10750 
14000 
20750 
26000 
36750 
43250 
62500- 


Suction 

3" 

4" 

5" 

6" 

6" 

7" 

8" 

10" 

12" 


Discharge 

3" 

4" 

5" 

6" 

6" 

7" 

8" 
10" 
10" 


6'-7' 

V-9' 
8'-2' 
8'-8' 
9'-6' 
9'-8' 


B 

2'-3" 
2'-6" 
3'-0" 
3'-6" 
4'-0" 
4'-6" 
4'-6" 
5'-0" 
5'-0" 


10K" 

13" 

15" 


D 

W 


18" 

1834" 
2ly2" 


2434" 

2'-2# 

2'-2" 

2'-8" 

2'-S" 


3'-0" 


E 

22" 
2'-6" 
3'-0" 
3'-3" 
3'-6" 
3'-9" 
3'-9" 
4'-4" 
4'-4" 


NOTES  ON  POWER  PLANT  DESIGN 


63 


THE  WHEELER  CONDENSER  AND  ENGINEERING  COMPANY 
DIMENSIONS  OF  WHEELER  ROTATIVE  DRY  VACUUM  PUMP 


Size 

5-12-12 
7-14-14 
7-16-10 
9-18-16 
9-22-16 
10-26-18 
12-30-18 
14-34-18 
16-30-24 
16-36-24 


Capacities  for 
Condenser  Surface 

in  Ibs.  per         Size 

hr.  28  '  Vac.     Suction 


18000 

27400 

34600 

48000 

08600 

102600 

130000 

154600 

160000 

197000 


4" 

5"2 

6" 

8" 

9" 
10" 
14' 
10" 
16" 
Note 


Size 

Discharge 
2" 
3" 
3" 
4" 
W 
5" 
6" 
6" 
6" 
8" 


11'32-s" 
11  -W 
13-4" 


B 

3'-l" 

3'-6" 

3'-8" 

4'-3" 

4'-7" 


6'-4" 

6'-7^ 

6'-5" 


C 

3'-3" 
3'-6" 
3'-6" 
4'-6" 
4'-6" 
5'-6" 
5'-6" 
5'-6" 
7'-0" 
7'-0" 


qD 


20" 
22" 
24" 


3'-4" 
3'-5" 


3'-4" 
3'-4" 


5'-0" 
5'-0" 

5'-3 

5'-9" 
5'-9" 


: — For  26"  Vacuum  capacity  may  be  doubled. 
For  27"  Vacuum  capacity  is  50%  greater. 
For  28^"  Vacuum  capacity  is  25%  less. 


LONGITUDINAL    SECTION    OF   AIR  CYLINDER 

"howing  Rotative  Valve  and  Flash  Port  for  minimizing 
clearance  less. 


WHEELER  PATENT  CCMPOUND   DISCHARGE 
VALVE 

The  lift  if  regulated  by  outside  adjusting  screws;  if  water 
collects  in  the  cylinder  the  secondary  spring  compresses 
and  gives  extra  large  lift. 


64 


NOTES  ON  POWER  PLANT  DESIGN 


THE  WHEELER  CONDENSER  AND   ENGINEERING   COMPANY 
WHEELER  DUPLEX  HOT  WELL  PUMP 


Capacity 

Ibs.  per 

Size 

hour 

Ruction 

3x2^x3 

4200 

2" 

4^x4x4 

11500 

2^" 

5^x4^x5 

19000 

3" 

6x5^x6 

33500 

4" 

6x7^x6 

57000 

6" 

6x8^x6 

73500 

6" 

7^x8^x10 

98000 

10x10x10 

142000 

8" 

10x12x10 

195600 

10" 

Discharge 


3" 
5" 
5" 

7" 


A 

21%' 
S'-eS-i 


4'-0' 


3'-10K 
4'-0" 


C 

%" 
17  H' 


D 


14" 
16" 
22" 


E 


8k" 


15" 
15" 


NOTES  ON  POWER  PLANT  DESIGN 


65 


THE  WHEELER  CONDENSER  AND  ENGINEERING  COMPANY 
WHEELER  CENTRIFUGAL  PUMP 


Gallons  per 

Size 

Minute 

A 

B 

C 

D 

4" 

400-475 

18fi" 

12% 

*  99                         1  K  i  /It 

15^4 

9^4" 

5" 

600-725 

22" 

\*2y. 

20^" 

UK" 

6" 

900-1050 

23" 

15' 

22^" 

12" 

8" 

1600-1900 

2'-3j^" 

16' 

21/^g" 

14/^" 

10" 

2500-3000 

2'-7" 

18' 

24tf"H 

16" 

12" 

3500-4200 

3/-J£" 

22' 

lg  i^" 

14" 

4800-5600 

3'-6" 

22' 

2'-67xg" 

21^" 

16" 

6400-7500 

3'-9" 

23^ 

'                     9'  Cl/" 
^  "0/^4 

23J4" 

18" 

8000-9500 

4'-!^" 

2'-l 

3'-2" 

2'-0" 

20" 

10000-11600 

4'-l" 

2'-3 

2'-ll" 

22K" 

24" 

14000-17000 

4'-10^" 

2'-8 

4'-0" 

2'-4" 

30" 

22000-26000 

5'-4" 

3'-3 

3'-10" 

3'-2" 

2'-2" 

2'-9"4 


4'-0 


-F 

1^" 

l'-F'" 


3'-4" 


4'-8" 
5'-7" 


66 


NOTES  ON  POWER  PLANT  DESIGN 


C.  H.  WHEELER  SPECIAL  EXHAUST  GATE   VALVE 


DIMENSIONS 


H 


K 


32 


16 
16 
21 
25 


M 
16 
20 
20 
24 
36 
36 


Surface  Condenser  with  Multiflex  Automatic  Relief  Valve,  Gate  Valve  and  Expansion  Joint. 


NOTES  ON  POWER  PLANT  DESIGN 


67 


THE  C.  H.  WHEELER   "MULTIPLEX"   PATENT  EXHAUST  RELIEF  VALVE 

This  valve  consists  of  a  brass  valve  deck  which  is  ihdived  into  a  number  of  rectangular  ports 

•anged  in  rows,  each  port  accurately  faced  on  an  angle  and  covered  by  a  flap  valve  made  of  Phos- 

jnor  Bronze  sheet,  coiled  at  one  end.     The  valves  in  each  row  are  mounted  on,  and  controlled  by 

•tted  bronze  stem,  to  one  end  of  which  is  keyed  a  bronze  crank;  these  cranks  have  a  common 

ctmg  rod  which  communicates  with  an  external  lever  and  locking  device  which  not  onlv 

allows  the  valves  to  be  secured  in  either  an  open  or  closed  position,  but  the  valves  can  be  seated 

with  any  desired  degree  of  tension,  because  of  the  coiled  spring.     The  angle  of  the  ports  and  valve 

ds  abrupt  turns  and  gives  the  steam  an  easy,  smooth  and  noiseless  passage  through  the 

+•  ^  non?a!  °Peration  the  vacuum,  or  unbalanced  condition  of  the  atmosphere,  holds  the  valve* 
tightly  on  their  seats;  but  to  insure  absolute  tightness  for  high  vacuum  service,  a  water  seal  with 
brass  globe  valve  on  inlet  side  and  visible  funnel  overflow  with  drain  connection  on  discharge  is 
provided. 


Size  of 
Valve 

A 
6 
8 

10 

12 

14 

16 

18 

20 

24 

30 


B 

28^ 


DIMENSIONS 

D 
11 


29 
29 
37 
42 
37 
45 
56 
64 


12 
13 

21 


26 


16 

19 

21 

23^ 

25 

27K 
32 

38% 


Shipping  Weight 

330  Ibs 

384 

900 

975 

1128 

1440 

1995 

2440 

3822 

6000 


68 


NOTES  ON  POWER  PLANT  DESIGN 


KNOWLES  VERTICAL  AUTOMATIC   EXHAUST   RELIEF  VALVE 


With  screw  lifting  device 


s 

D 

L 

H 

A 

B 

HH 

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1  - 

Height 

Distance 

T       " 

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II 

Number 
and  Size 

Size 

^    c 
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si 

Width 

Height 

above 

below 

Height 
Over  All 

1  E 

1  5 

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of  Bolts 

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S 

Centre 

Centre 

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a 

4 

9 

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Double  dash  pot  with  screw  lifting 
device 


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Thick- 
ness of 
Flanges 

Diarn. 
of  Bolt 
Circle 

Number 
and  Size 
of  Bolts 

Size 

Diam. 
of 
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Height 
Face  to 
Face 

Length 

Wi.lih 

Height 

Distance 
from 
Centre  to 
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4 

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9 

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1 

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27 

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28-14 

NOTES  ON  POWER  PLANT  DESIGN 


FLOW  OF   STEAM  IN  PIPES 

The  area  of  a  steam  pipe,  if  the  pipe  is  of  short  length,  may  be  calculated  by  dividing  the 
volume  of  steam  to  be  delivered  per  minute  by  an  assumed  velocity  of  flow.  For  engines  of  the 
Corliss  type  taking  steam  in  large  quantities  intermittently,  a  velocity  not  exceeding  6000  feet 
per  minute  may  be  used.  A  receiver  having  a  volume  equal  to  three  times  the  capacity  of  the 
high  pressure  cylinder  is  sometimes  placed  close  to  the  throttle  valves  of  such  engines.  This  re- 
ceiver furnishes  a  reservoir  from  which  the  engine  draws  steam ;  it  enables  a  smaller  steam  pipe  to 
be  used  and  thereby  prevents  the  vibrations  of  the  steam  main  which  are  so  common  in  plants 
where  slow  speed  engines  are  in  use.  For  steam  turbines  or  high  speed  engines  which  practically 
make  a  steady  flow  a  velocity  as  high  as  10,000  feet  per  minute  may  be  used.  The  drop  in  pressure 
in  a  pipe  of  long  length  may  be  calculated  by  the  formulae  proposed  by  Mr.  G.  H.  Babcock.  These 
formulae  are  based  on  actual  tests  made  on  pipes  up  to  4"  in  diameter,  and  it  is  probable  that  the 
results  will  hold  good  for  pipes  of  even  larger  size.  Similar  tests  were  conducted  by  R.  C.  Carpenter 
and  a  formula  derived  which  is  practically  the  same  as  that  proposed  by  Babcock.  In  the  formula : 

w  =  weight  of  steam  in  Ibs.  per  minute. 

d  =  diameter  of  pipe  in  inches. 

L  =  length  of  pipe  in  feet. 

P  =  drop  in  pressure  in  Ibs.  per  sq.  inch. 

y  =  mean  density  in  Ibs.  per  cu.  ft. 

V  =  velocity  in  feet  per  minute. 


V  =  19,590        '  Pd 


P=  .0001321 -*--* ~ 


VELOCITY  OF   EXHAUST  STEAM 

The  velocity  of  exhaust  steam  is  taken  from  6000  feet  per  minute  for  steam  at  3  pounds  back 
pressure  to  40,000  feet  per  minute  at  a  29.5"  vacuum.  As  the  pressure  gets  lower  the  velocity 
increases,  and  some  engineers  use  velocities  which  would  increase  from  20,000  feet  per  minute 
at  a  26"  vacuum  to  35,000  feet  per  minute  for  a  29"  vacuum.  There  has  been  in  the  past  but 
little  information  as  to  the  drop  in  pressure  or  the  loss  of  vacuum  due  to  these  high  velocities. 
Two  series  of  experiments  were  carried  on  in  the  engineering  laboratories  at  M.I.T.  to  determine 
the  loss  of  pressure  with  such  velocities.  These  experiments  were  with  a  pipe  6"  in  diameter. 

While  the  results  apply  specifically  to  a  pipe  of  about  this  size  it  is  probable  that  the  equations 
may  be  used  for  pipes  of  larger  sizes.  No  doubt  the  drop  in  pressure  in  the  larger  size  pipe  will 
be  less  than  given  by  the  equation.  These  experiments  cover  a  range  from  a  25"  vacuum  through 


70  NOTES  ON  POWER  PLANT  DESIGN 

29^".    The  formulae  proposed  are  modifications  of  the  Babcock  formula  and  the  letters  used  have 
the  same  meaning,  i.  e.: 

L  =  the  length  of  pipe  in  feet. 

y  =  the  mean  density  of  the  steam  in  Ibs.  per  cu.  ft. 

V  =  mean  velocity  of  the  steam  in  ft.  per  min. 

P  =  difference  in  pressure  in  Ibs.  per  sq.  inch. 

d  =  diameter  of  the  pipe  in  inches. 


V  =  13,700         o  a\ for  straight  pipe. 


P  =  .0001791  -          -T-         /  for  straight  pipe. 
y  «5 


/  Pd 

V  =  9600         \ -  o  ft\  for  a  90°  elbow. 


V  =  7200         \/  --  <T~A~\  for  two  90°  elbows  making  a  return  bend. 

"  '  " 


The  accuracy  of  the  work  does  not  warrant  calculation  of  results  within  velocities  of  500  feet 
either  side  of  the  true  velocity. 

Problem  to  Illustrate  Application  of  Formula.  Suppose  that  the  exhaust  pipe  leading  from 
a  turbine  to  a  condenser  is  15'  long,  20"  diameter,  with  an  elbow  at  each  end.  If  it  be  assumed 
that  the  steam  has  a  mean  velocity  of  30,000  feet  per  minute,  what  will  be  the  drop  in  pressure 
between  the  turbine  and  the  condenser?  The  vacuum  midway  between  the  turbine  and  the  con- 
denser being  28%",  barometer  29.95". 

The  absolute  pressure  is  .933  Ibs.  and  the  specific  volume  of  steam  at  this  pressure  is  355  cu.  ft. 


P  X  20 
For  the  straight  pipe  30,000  =  13,700\' 


1       i*/,     3.6\ 

T55xl5(1+To) 


P  =  .012  Ibs. 


/  P  X  20  . 

For  each  elbow  30,000  =  9600  \  -j—  —3- 


355  20 

P  =  .003 

Note: — The  length  of  the  elbow  is  taken  as  2  ft.  along  the  center  line. 
The  total  loss  is  .012  +  .003  +  .003  =  .018  Ibs. 

.018 

-T^T  =  .04    of  mercury  pressure. 

The  loss  resulting  from  an  elbow  is  equivalent  to  the  loss  in  a  piece  of  straight  pipe  having  a  length 
a  little  greater  than  twice  the  distance  along  the  center  line  of  the  elbow. 


NOTES  ON  POWER  PLANT  DESIGN  71 

Example  to  Illustrate 

An  engine  is  connected  to  a  barometric  tube  condenser  through  40  feet  of  vertical  pipe,  10 
feet  of  horizontal  pipe  and  three  elbows;  one  elbow  being  located  at  the  exhaust  opening  of  the 
cylinder  and  the  second  and  third  elbows  being  on  the  vertical  pipe  leading  to  the  condenser. 

The  exhaust  pipe  is  12"  diameter  and  the  vacuum  to  be  maintained  is  26",  with  the  barometer 
at  30.1".  If  the  maximum  difference  in  pressure  between  the  condenser  and  the  engine  is  to  be 
not  over  .1"  of  Hg.  how  many  pounds  of  steam  per  hour  can  be  put  through  this  12"  pipe? 

The  length  through  the  center  of  a  12"  elbow  is  about  1  foot  so  that  about  1x2x3=6  feet 
should  be  added  to  the  length  of  the  pipe  making  a  total  of  56  feet. 


.0491  x  12 
F  =  13,700  \— j-  ~T1T\  v  =  16,150  ft.  per  min. 

172  X  56  ° 
16150  x  .7854  x  60 


172 
Had  .2"  mercury  been  the  greatest  drop  allowed 


.2  x  .491  x  12  x  172 
F  =  13,700  \  o  fi\  F  =  22,850 


and  10,400  Ibs.  could  be  taken  care  of  through  the  12"  pipe. 


72  NOTES  ON  POWER  PLANT  DESIGN 


FEED  WATER  HEATERS 

Feed  water  heaters  are  of  two  classes,  open  heaters  and  closed  heaters. 

In  an  open  heater  the  water  can  not  be  heated  above  212°  while  in  a  closed  heater  higher 
temperatures  than  212°  are  possible. 

A  primary  heater  is  a  heater  placed  on  the  exhaust  pipe  between  the  main  engine  or  turbine 
and  the  condenser. 

A  secondary  heater  which  may  be  either  an  open  or  a  closed  heater  utilizes  the  heat  of  the 
auxiliaries,  exhausting  at  atmospheric  pressure,  in  raising  the  temperature  of  the  water  leaving  the 
primary  heater  to  a  temperature  within  8  or  10  degrees  of  that  of  the  exhaust  steam.  From  the 
secondary  heater  the  water  passes  through  the  economizer  (if  one  is  used)  to  the  boiler. 

A  feed  water  heater  is  very  much  like  a  surface  condenser  and  consequently  the  same  laws, 
regarding  the  interchange  of  heat  per  square  foot  of  surface  per  degree  difference  of  temperature, 
apply. 

The  interchange  of  heat  in  condensers  was  found  to  be  proportional  to  the  square  root  of  the 
velocity  of  the  water  through  the  tubes.  Feed  water  heaters  designed  for  torpedo  boats,  etc., 
where  space  is  very  limited  have  been  made  with  the  water  flowing  at  high  velocity  in  the  annular 
space  between  two  tubes  placed  one  inside  the  other.  The  high  velocity  of  water  gives  a  large 
interchange  of  heat  but  requires  8  or  10  Ibs.  additional  pressure  on  the  pump  forcing  the  water 
through  the  heater. 

The  C.  H.  Wheeler  Co.  use  the  following  formula  in  figuring  the  surface  needed  in  a  closed  heater: 

S  =  sq.  ft.  surface 
W  =  Ibs.  of  water  per  hour 
ta  =  temperature  of  steam  °F. 
tc  =  temperature  of  cold  water  entering  °F. 
th  =  temperature  of  hot  water  leaving  °F. 
K  -  constant  of  transmission  taken  as  250 

-W  2.3026  logw  ^r 


It  is  always  safer  to  put  in  a  larger  heater  than  appears  at  first  to  be  necessary. 
Tables  of  dimensions  of  both  a  Primary  and  a  Secondary  heater  are  given.     These  tables 
will  give  the  general  dimensions  only. 

The  feed  piping  at  a  heater  should  be  arranged  so  that  in  case  of  any  trouble  with  the  heater, 
the  water  can  be  by-passed  around  the  heater.  This  necessitates  three  valves.  The  piping  must 
be  of  brass  in  order  to  resist  the  action  of  the  hot  water. 


NOTES  ON  POWER  PLANT  DESIGN 


73 


Primary  Heater. 


1 

SHELL,  v 

TUBES. 

>           -f 
PIPING. 

Capacity  In  gallons 
at 
ooc  filling. 

I 

a 
1 

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If 

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S  S 

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bi      . 

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in 

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1 
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12 

20 

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15 

21 

25 

II.6 

r* 

4 

I 

6.0 

33 

300 

40 

12 

24 

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25 

31 

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4 

I 

9.8 

39 

435 

50 

14 

28 

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41  ' 

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163 

45 

625 

60 

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700 

75 

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28.0 

58 

875 

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56 

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57 

76 

46,0 

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6 

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393 

74 

iobo 

200 

20 

44 

2 

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45 

105 

63  4 

2 

8 

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45-6 

67 

1300 

250 

20 

54 

2 

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55 

126 

76.2 

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57-7 

77 

1650 

300 

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152 

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72 

1650 

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895 

80 

2450 

400 

30 

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2 

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204 

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78 

3470 

500 

3° 

58 

2 

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59 

245 

147  o 

3 

12 

2 

147.8 

88 

3800 

6OO 

30 

61 

2 

55 

62 

282 

'171.7 

3 

12 

2 

151.8 

9' 

4000 

700 

34 

58 

2 

68 

59 

333 

201  5 

3' 

12 

*,'* 

1868 

94 

4750 

800 

34 

68 

2 

68 

69 

39' 

236.4 

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83 

469 

282.9 

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264.2 

118 

5700 

In  computing  the  heating  surface  of  the  above  table  15  per  cent,  is  added  for  the  corrugations. 


74 


NOTES  ON  POWER  PLANT  DESIGN 


Secondary  Heater. 


a. 

L, 

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21 

700 

27 

84 

74 

1'A 

233-74 

4: 

4 

2 

34 

'3' 

18 

43% 

97^4 

3' 

"4 

37 

21 

800 

30 

102 

70 

»K 

268.48 

41 

4 

2 

38 

'33 

20 

49 

95 

M 

M 

41  X 

21 

900 

30 

102 

80 

')* 

306.85 

4 

14 

2 

38 

•43 

20 

49 

'°5 

34 

24 

41  '.j 

21 

IOOO 

32 

"4 

78 

l>0 

334.36 

4 

18 

2 

40 

143 

2O 

SI 

103 

34 

24 

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26 

1200 

32 

"4 

94 

>1A 

402.97 

S 

18 

2 

40 

'59 

20 

51 

l'9 

34 

40 

42'-.. 

26 

IJOO 

36 

144 

93 

I>2 

503.59 

5 

24 

3 

44 

162 

22 

S7 

119 

39 

44 

44 

32 

2OOO 

36 

'44 

124 

••x. 

671.80 

5 

24 

3 

44 

192 

22 

S» 

150 

J9 

75 

44 

32 

3000 

48 

258 

104 

i  T- 

100896 

6 

30 

3 

56 

181 

24 

66 

'30 

45 

60 

48 

3« 

4000 

48 

258 

'38 

i'x 

1338.87 

6 

3° 

3 

56 

211 

24 

66 

164 

43 

94 

48 

38 

SOOQ 

60 

402 

in 

>>a 

1677.99 

8 

30 

3 

68 

2O2 

26 

72 

'43 

47 

75 

5' 

38 

6qoo 

60 

402 

'35 

'* 

2038.51 

8 

30 

3 

68 

226 

26 

72 

167 

47 

99 

S2 

38 

A  type  of  feed  water  heater  which  has  been  recently  developed  by  Shutte  and  Koerting  Co. 
for  use  in  battleships,  torpedo  boat  destroyers  and  places  where  saving  of  space  is  an  item,  is  shown 
by  the  sectional  cut  which  follows. 

In  this  type  of  heater,  the  water  to  be  heated  is  sent  through  a  narrow  space  between  sets 
of  corrugated  tubes.  The  lower  tube  in  the  cut  referred  to  shows  one  set  of  tubes  in  section.  The 
steam  which  heats  the  water  is  on  the  outside  of  the  larger  corrugated  tube  and  on  the  inside  of 
the  inner  corrugated  tube.  The  feed  water  is  sent  through  these  tubes  under  high  velocity  and, 
due  to  the  fact  that  the  water  is  broken  up  into  a  thin  film,  it  is  possible  to  heat  it  to  within  a  very 
few  degrees  of  the  temperature  of  the  steam.  The  loss  in  head  in  passing  the  water  through  the 
heater  may  be  as  great  as  12  pounds.  Dimensions  of  the  different  sizes  of  the  heater,  together 
with  the  horsepower  rating  may  be  obtained  from  the  diagram  and  table  which  accompanies  the 
same. 


NOTES  ON  POWER  PLANT  DESIGN 


75 


DIMENSION  TABLE 


(Boiler 

Horse  Power 

Size          a 

it  3#  back 

No. 

Pressure 

A 

1 

80 

5'1" 

2 

160 

5'1" 

3 

330 

5'1" 

4 

500 

5'  3" 

5 

650 

5  '3" 

6 

830 

5'  3" 

7 

1000 

5'  5" 

S 

1150 

5'  5" 

9 

1300 

5'  5" 

10 

1500 

5'  7" 

11 

1660 

5'  7" 

12 

2000 

5'  7" 

13 

2330 

5'  9" 

14 

2700 

5'  9" 

15 

3000 

5'  9" 

16 

3300 

5'  11" 

B 


14" 
17" 
21" 
22" 
24" 
24" 
27" 
27" 
28" 
28" 
30" 
33" 
33" 
36" 
40" 


E 
4'  W 

4'  iy2" 

4'  iy2" 

4'  2" 
4'  2" 
4'  2" 


4'  2^ 
4'  3" 
4'  3" 
4'  3" 
4'  4" 
4'  4" 
4'  4" 
4'  5" 


Feed  Water 
Connections 
FWI    FWO 
1" 


2" 
2" 
2" 
3" 
3" 
3" 


4" 
4" 
4" 


Steam 
S 
2" 
3" 
3" 
4" 
4" 
4" 
5" 
5" 
5" 
6" 
6" 
6" 
7" 
7" 
7" 
8" 


Drain 
D 
1" 
1" 


2" 
2" 
2" 


3" 
3" 
3" 


76  NOTES  ON  POWER  PLANT  DESIGN 

COOLING  TOWERS 

The  amount  of  water  surface  in  a  cooling  tower  working  with  forced  air  circulation  varies 
from  23  to  27  square  feet  per  I.  H.  P.  More  surface  is  needed  in  a  natural  draft  tower  than  in 
a  fan  towerv  in  general  the  surface  being  double  that  of  a  forced  draft  tower.  The  amount  of  air 
needed  depends  to  a  large  extent  upon  the  humidity  of  the  air  entering  the  tower.  The  air  leav- 
ing the  tower  is  either  saturated  or  nearly  so. 

It  is  not  advisable  to  send  an  abnormal  amount  of  air  through  a  tower,  as  the  cost  of  the  in- 
creased power  needed  to  run  the  fan  and  the  greater  shrinkage  due  to  evaporation,  amount  to  more 
than  the  gain  made  by  the  increased  vacuum  on  the  engine,  resulting  from  the  cooler  circulating 
water,  will  offset. 

The  materials  used  inside  of  a  cooling  tower  to  expose  as  large  a  surface  of  cooling  water  as 
possible  to  contact  with  the  air  without  at  the  same  time  obstructing  the  free  flow  of  air,  are  tiers 
of  the  tile  pipes  6" diameter,  2  feet  long,  used  by  the  Worthington  Company,  galvanized  iron  wire 
screens  set  nearly  vertical,  used  by  the  Wheeler  Company,  galvanized  iron  troughs  set  horizontally 
and  arranged  so  that  the  water  flows  from  trough  to  trough  as  it  descends  (Jennison  tower),  boards, 
brush,  or  other  material. 

The  amount  of  air  to  be  supplied  to  a  tower  and  the  shrinkage  of  water  from  evaporation 
may  be  calculated  approximately  from  the  following  equations: 

Z  =  weight  of  cooling  water  entering  condenser  per  Ib.  of  steam. 

E  =  weight  of  water  evaporated  from  tower  per  Ib.  of  steam  condensed. 

Vc  =  cu.  ft.  of  cold  air  entering  tower  per  Ib.  of  steam  condensed. 

This  air  may  enter  by  natural  draft,  or  as  is  most  often  the  case  it  may  be  sent 
in  by  disc  fans. 

V  Th 
Vh  =  cu.  ft.  of  hot  air  leaving  tower  per  Ib.  of  steam  condensed  =     _  - 

•L  c 

Y  =  the  wt.  of  air  entering  the  tower  may  be  figured  thus: 

Vc V, 


29.92  x  12.39     TC 

491.5         Pc  Pe 

Tc  =  absolute  temperature  of  air  entering. 

PC  =  absolute  pressure  of  air  entering  tower  in  ins.  of  mercury. 

If  the  excess  pressure  of  the  air  entering  the  tower  is  measured  by  the  difference 


of  water  level  in  a  U-tube,  Pc  =  the  sum  of  the  barometer  reading  and times  the 

difference  of  water  level.     This  excess  pressure  can  usually  be  neglected. 

Qh  and  Qc  are  the  heats  of  the  liquid  corresponding  to  the  temperatures  of  the  hot  and  cold 
condensing  water. 

Yh  and  Yc  are  the  weights  of  water  carried  by  a  cu.  ft.  of  saturated  air  at  temperatures  th  and 
te  respectively.  See  curves 

Z  x  (Qh  -  Qc)  = e-jjr  X  .24  (th  -  tc)  +  r  (.90  x  Vh  Yh  -  relative  humidity  x  Vc  Yc) 

.754-i-' 

th  and  tc  are  temperatures  of  air  at  top  of  tower  and  at  entrance  to  tower,  r  is  the  heat  of 
evaporation  corresponding  to  the  temperature  of  the  air  at  top  of  the  tower.  The  temperature  of 
the  air  at  the  top  of  the  tower  is  from  10  to  25  degrees  lower  than  the  temperature  of  the  hot  con- 
densing water  taken  where  it  enters  the  tower. 


NOTES  ON  POWER  PLANT  DESIGN  77 

In  making  a  calculation  for  a  tower  it  is  probably  safe  to  assume  a  difference  of  15  degrees. 
The  air  leaving  the  tower  may  be  saturated  or  only  partially  saturated,  the  condition  depending 
upon  the  amount  of  air  sent  in  and  the  design  of  the  tower.  In  general  it  is  a  good  plan  to  assume 
that  the  air  at  the  top  of  the  tower  is  only  90%  saturated  and  that  the  temperature  of  this  air 
is  15  degrees  lower  than  the  temperature  of  the  hot  water  entering  the  tower.  These  assumptions 
have  been  made  in  the  calculations  which  follow. 

E  =  .90  x  Vh  Yh  -  relative  humidity  x  Vc  Ye 

In  the  case  of  a  jet  condenser  the  steam  condensed  adds  one  pound  to  each  Z  pounds  of  cooling 
water  entering  the  condenser. 

If  E  is  greater  than  one  pound  then  the  excess  must  be  supplied  as  make-up  water. 
For  a  surface  condenser  E  represents  the  make-up  water. 

Problem. 

A  cooling  tower  receives  water  from  a  surface  condenser  at  122°  F.,  the  water  leaves  the  cooling 
tower  at  90°  F.;  temperature  of  outside  air  72°,  relative  humidity  80%. 

Temperature  of  condensed  steam  95°,  vacuum  in  condenser  25",  barometer  29.7". 

Engine  of  500  H.  P.  and  consumes  20  pounds  of  steam  per  H.  P. 

What  is  the  amount  of  air  needed  per  pound  of  steam  condensed  and  what  is  the  per  cent 
loss  of  cooling  water  due  to  evaporation? 

1053.2  -  63.1  __990.J_ 
90.0  -  58.1     =    31.9 

Vc  x  566.5  x  .00347 


c  ,,,      79  t 

=   .754  x  531.5   X  >24  531.5 

29.7  |    l 

-  .8  Vc  x  .00124  [ 

The  figures  .00347  and  .00124  are  the  Ibs.  of  water  required  to  saturate  a  cu.  ft.  of  dry  air  at 
107  and  at  72  deg.  respectively.  The  figure  1031.8  is.  the  value  of  the  heat  of  vaporization  at 
107°. 

990.1  =  3.036  Vc  Vc  =  326  cu.  ft. 

E  =  (.00333  -  .00099)  Vc  =  .763  Ibs.  evaporation  per  Ib.  of  steam  condensed  or  per  31.8  Ibs.  of 
circulating  water. 


This  is  ^r  •  -5-  =  .0240  or  2.40%  shrinkage.     As  the  first  term  of  the  right  hand  side  of  this  equation 
ol  .  o 

623 

evaluates  .623  Fc  it  is  evident  that  the  heat  carried  off  by  the  air  is  5—5^   percentage  of  the  total 

o  . 


amount  abstracted.    This  figures  as  20.5%;  the  heat  taken  out  by  evaporation  being  79.5%. 

To  illustrate  more  fully  the  use  of  the  equation  and  to  illustrate  also  the  extra  cost  (at  the  cooling 
tower)  of  a  high  vacuum  over  a  moderate  vacuum,  two  cases  will  be  taken  up  :  First  a  condensing 
and  cooling  outfit  maintaining  a  28"  vacuum  and,  second,  a  similar  outfit  maintaining  a  26"  vacuum. 

The  illustration  will  be  worked  through  -for  each  case  with  relative  humidities  of  the  enter- 
ing air  as  90,  as  70,  and  as  50% 

First  case  —  A  condenser  maintaining  a  28"  vacuum  with  hot  condensing  water  at  95°  or 
7  degrees  below  the  temperature  corresponding  to  the  vacuum.  The  exhaust  steam  is  assumed 
to  contain  4%  of  moisture.  The  temperature  of  the  air  may  be  taken  as  72°  and  it  will  be  assumed 
that  the  tower  is  to  cool  the  water  to  this  temperature. 

For  air  90%  saturated  at  72°  the  volume  required  per  pound  of  steam  =  Vc  may  be  cal- 
culated thus:  To  abstract  the  heat  from  a  pound  of  exhaust  steam  43.5  Ibs.  of  cooling  water  would 


78  NOTES  ON  POWER  PLANT  DESIGN 

be  the  minimum  weight  required,  since  1000  heat  units  are  to  be  abstracted  from  each  pound  of 
steam  with  an  increase  in  temperature  in  the  circulating  water  of  23°. 


V    v 

1000  =  J^rj-r  X  24  {    (95  -  15)  -  72     [      +  1046.6  \  .9    Ve*-  X-0,0158 

754  5ol  5 
.    '         29.92  ) 

-  .9  Vc  x.0.0124 

1000  =  .143  Vc  +  1046.6  (.00144  -  .00112)  Vc 
1000  =  .143  Vc  +  .335  Vc  Vc  =  2100  cu.  ft. 

The  evaporation  =  .00032  x  2100  =  .672  Ibs. 

Of  this  total  heat  abstracted  the  heating  of  the  air  accounts  for  30  per  cent  and  the  evaporation 
70  per  cent. 

Similar  calculations  for  70  per  cent  and  for  50  per  cent  humidities  give 

Percent  Cu.  ft.  air  Evap.  per  Ib.  Per  cent  heat  Per  cent  heat 

humidity  per  Ib.  of                 of  exhaust  abstracted  by  abstracted  by 

entering  air  exhaust                  condensed                   the  air  vaporization 

90  2090                         .672                           30                            70.0 

70  1350                          .770                          19.4                           80.6 

50  990                         .812                          14.1                           85.9 

Second:  Suppose  that  the  vacuum  to  be  carried  is  26"  with  air  at  72°  and  hot  condensing 
water  at  119°  or  7  degrees  below  the  temperature  corresponding  to  the  vacuum.  Cold  water  at 
72°;  and  4  per  cent  moisture  in  the  exhaust  steam. 

The  heat  to  be  abstracted  per  pound  of  exhaust  is  983  B.  T.  U.  and  20.9  Ibs.  of  cooling  water 
is  the  minimum  required  per  pound  of  exhaust.  From  calculations  similar  to  the  preceding  it 
appears  that  the  amounts  of  air  needed  and  the  evaporations  are: 

Relative                     Cu.  ft.                 Evaporation           Per  cent  heat  Per  cent  heat 

humidity                        air                       in  pounds              abstracted  by  abstracted  by 

the  air  vaporization 

90                            386                            .737                         22.5  77.5 

70                            350                            .756                         20.8  79.2 

50                            321                            .773                          18.7  81.2 

The  amount  of  water  evaporated  per  pound  of  steam  condensed  is  about  the  same  in  each  ca.se. 

In  the  first  case  with  70  per  cent  humidity  the  evaporation  was  .770  in  43.5  Ibs.  of  water  sent 
into  the  tower,  or  1.8%. 

In  the  second  case  with  70  per  cent  humidity  about  3.6%. 

The  curve  showing  the  pounds  of  water  needed  to  saturate  one  pound  of  air  at  any  tempera- 
ture may  be  constructed  very  quickly  from  values  taken  from  any  steam  tables. 

Example. —  The  amount  of  water  required  to  saturate  one  cubic  foot  of  air  at  88°  F.  is  .002 
Ib.  If  the  air  was  of  a  relative  humidity  of  60  to  start  with,  then  40  x  .002  would  be  the  amount 
the  air  would  take  up  in  becoming  saturated  and  the  B.  T.  U.  abstracted  would  be 

1042.2  x  .40  x  .002  =  .834  per  cu.  ft.  of  air. 


PER  CENT  OF  ENGINE  POWER  REQUIRED  BY  COOLING  TOWER  FAN  AND  BY 
THE  EXTRA  DISCHARGE  HEAD  ON  THE  CIRCULATING  WATER 

Referring  to  the  first  case  already  cited,  with  relative  humidity  of  70,  1350  cu.  ft.  of  air  were 
needed.  Suppose  a  disc  fan  is  to  be  used  and  a  dynamic  head  of  .3"  of  water  maintained  at  the 
fan.  As  the  static  head  is  zero  the  velocity  head  will  be  .3". 

This  velocity  pressure  corresponds  at  70°  to  a  velocity  of  2200  ft.  per  minute.     Suppose  the 


NOTES  ON  POWER  PLANT  DESIGN  .  79 

engine  uses  14  pounds  of  steam  per  H.  P.  per  hour,  then  the  steam  per  minute  is  14/60  Ibs.  and 
the  cu.  ft.  of  air  sent  through  the  tower  is  14/60  x  1350. 

The  H.  P.  input  to  the  fan  is,  for  this  case,  if  30  per  cent  is  assumed  as  fan  efficiency: 

.3"  x  5.2  x  14/60  X  1350 


'     "  33000  X  .30 

of  engine  power. 

To  this  should  be  added  the  power  due  to  pumping  14/60  x  43.5  pounds  of  cooling  water 
per  minute  through  an  additional  head  of  about  30  feet.  This  amounts  to  .00889  H.  P. 

If  the  fan  were  driven  by  a  small  engine  using  35  pounds  of  steam  per  H.  P.  hour  and  the 
circulating  apparatus  were  also  steam  driven  using  40  Ibs.  per  H.  P.  hour,  then  the  extra  steam 
required  by  the  cooling  tower  outfit  would  be 

2  10 

.050  x  35  +  .0089  x  40  =  2.10  and  -    -  =  .15  or  15.0  per  cent  additional. 

14 

A  similar  calculation  for  the  second  case  with  26°"  vacuum,  70%  humidity  with  engine  using 
15  pounds  of  steam  per  H.  P.  hour  gives: 

15 

Air  per  minute  =  777:  X  350 
oO 

.3  x  5.2  x  ~  X  350 


-'  33000  x  .30 

20.9  x~  X  30 
Extra  H.  P.  on  circulating  pump  =       —          -  =  .00472 

ooUUU 

If  fan  engine  and  circulating  apparatus  were  steam  driven  then  using  same  rate  as  before 

.0137  x  35  +  .00472  x  40  =  .668 
.668 


15 


=  .0445  or  about  4.45%  additional. 


If  the  cooling  surface  used  in  the  tower  offers  much  resistance  to  the  free  discharge  of  air  from 
the  fan  through  the  tower,  it  may  be  necessary  to  run  the  fan  at  higher  velocity  which  increases 
the  work  of  driving. 

In  the  Wheeler  Barnard  cooling  tower  the  cooling  surface  consists  of  galvanized  wire  screens 
placed  in  parallel  vertical  rows  about  3"  apart.  Water  is  distributed  to  the  tops  of  these  screens 
by  U-shaped  troughs  each  trough  supplying  two  screens.  In  this  way  as  each  side  of  a  screen  is 
figured  as  cooling  surface,  8  sq.  ft.  of  surface  is  obtained  per  cubic  foot  of  volume  in  the  screen 
section  of  the  tower.  But  little  resistance  is  offered  to  the  passage  of  air  between  the  screens. 

From  experiments  made  by  the  company  it  is  found  that  ordinarily  eleven  feet  of  vertical  length 
of  screen  offers  sufficient  evaporating  surface  to  saturate  the  air.  The  tower  is  square  or  rectangular 
in  section  and  the  number  of  fans  needed  depends  upon  the  size  of  the  tower. 

The  B.  T.  U.  per  hour  per  square  foot  of  surface  in  a  cooling  tower  apparently  varies  from  200 
to  900. 

It  is  not  possible  to  get  figures  for  a  square  foot  of  surface  which  will  apply  to  every  type  of 
tower  since  with  different  kinds  of  surface  there  is  a  variable  amount  of  spraying;  even  with  the 
same  surface  this  spraying  varies  with  the  quantity  of  water  flowing;  and  consequently  there  is 
available  an  unknown  amount  of  surface  besides  that  provided  in  the  tower. 

A  drop  of  water  .178"  in  diameter  weighs  .75  grains  and  the  surface  of  a  number  of  drops  suffi- 
cient to  make  a  gallon  would  be  about  54  square  feet. 

Cooling  towers  are  occasionally  placed  on  the  roof  of  buildings.    By  using  a  surface  condenser 


80  NOTES  ON  POWER  PLANT  DESIGN 

the  extra  work  on  the  up  leg  of  the  circulating  water  is  practically  offset  by  the  gain  from  the  down 
leg  and  there  is  simply  the  friction  in  the  extra  lengths  of  piping  to  make  additional  work  for 
the  circulating  pump. 

Where  one  tower  is  used  for  a  number  of  condensers  having  centrifugal  circulating  pumps  it 
is  advisable  to  have  a  separate  discharge  pipe  from  each  centrifugal  to  the  tower. 

Towers  cost  above  the  foundation  from  $2.60  to  $4.00  per  K.  W.  capacity. 

» 

SPRAY  NOZZLES 

By  spraying  water  into  the  air  a  cooling  may  be  effected  through  the  evaporation  of  a  part 
of  the  water  just  as  was  the  case  in  the  cooling  tower. 

The  total  exposed  surface  of  the  sprayed  jet  meets  less  air  per  pound  than  in  the  cooling  tower, 
and  on  this  account  it  is  often  advisable  to  spray  30  to  50  per  cent  of  the  water  a  second  time  before 
sending  it  through  the  condenser. 

Generally  spray  nozzles  of  the  size  known  as  2"  are  the  most  economical.  The  2"  size  screws 
on  to  a  2"  outlet;  the  opening  in  the  nozzle  tip  being  about  .8".  As  many  nozzles  should  be  pro- 
vided as  are  needed  to  discharge  the  entire  weight  of  condensing  water  under  a  pressure  of  not 
over  15  Ibs.  gage  at  the  nozzle. 

The  nozzles  should  be  set  from  8  to  10  feet  apart  if  2";  a  greater  distance  if  over  2".  Where 
a  considerable  number  of  nozzles  are  used  it  is  customary  to  have  the  water  which  is  sprayed  into 
the  air  fall  back  into  an  artificial  pond  one  or  two  feet  deep.  When  a  number  of  nozzles  are  in  use 
the  aspirator  action  exerted  by  the  jets  causes  a  current  of  air  to  flow  along  the  surface  of  the  pond 
from  the  edge  towards  the  centre.  This  current  of  air  assists  to  some  extent  in  the  cooling. 

In  some  few  instances  spray  nozzles  have  been  put  along  the  edges  of  a  narrow  brook  and  the 
falling  spray  caught  on  board  fences  inclined  30°  with  the  ground  and  draining  into  the  brook. 

There  are  one  or  two  small  plants  where  the  cooling  nozzles  discharge  on  to  the  roof  of  the 
building.  From  tests  made  in  the  Engineering  Laboratories  of  the  Massachusetts  Institute  of 
Technology  on  the  Schutte  Koerting  nozzles  it  seems  that 

1°  The  temperature  of  the  water  after  spraying  is  more  dependent  upon  the  temperature 
and  humidity  of  the  atmosphere  and  upon  the  fineness  of  the  spray  than  upon  the  initial  tem- 
perature of  the  water.  Therefore  it  is  advisable  to  spray  the  water  as  hot  as  may  be  without 
excessive  steaming. 

2°  At  high  humidity,  80%  or  90%,  the  temperature  of  the  water  may  be  lowered  to  within 
12°  F.  or  13°  F.  of  the  temperature  of  the  air,  with  a  total  drop  in  temperature  of  35°  F.  to  40°  F. 

3°  At  low  humidity  20%  to  30%,  the  temperature  of  the  water  after  spraying  may  be  as  much 
as  8°  F.  below  the  temperature  of  the  air  and  the  total  drop  in  temperature  40°  F.  to  45°  F. 

4°  The  loss  of  water  by  evaporation  is  approximately  .15  pounds  per  degree  lowering  of 
temperature  per  100  pounds  of  water  discharged,  or  a  gross  loss  of  about  6%  for  40°  F.  lowering 
of  temperature.  In  no  case  was  the  loss  found  to  exceed  7%. 

The  discharge  of  these  nozzles  was  found  to  be  as  follows: 

Head  hi  ft.  Cu.  ft.  per  Cu.  ft.  per  min.                  Cu.  ft.  per  min. 

at  base  of  min.  for  1"  for  2"  pipe  for  3"  pipe 

nozzle.  pipe.    Diam.                  Tip  =  .800"  diam.            Tip  =  1.181"  diam. 
nozzle  at 
tip  .406" 

25  1.782  6.736  14.83 

30  1.952  7.379  16.24 

35  2.109  7.971  17.54 

40  2.254  8.521  18.75 

45  2.391.  9.036  19.89 

50  2.520  9.526  20.97 

55  2.643  9.991  21.99 

60  2.761  10.44  22.97 

65  2.873  10.86  23.91 


NOTES  ON  POWER  PLANT  DESIGN 


81 


.OO7C  

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s^                           ^^ 

O  .OOGO  --      ---•  -»3j  --- 

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tx                                                                                                           ^\ 

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w                                                                           ::*!jJ:i::: 

c§                                                                          t^ 

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SHSE  — 

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~7~emDerafure      of 


82  NOTES  ON  POWER  PLANT  DESIGN 


CENTRIFUGAL  PUMPS 

Centrifugal  pumps  either  single  or  multistage  are  replacing  the  reciprocating  piston  pump 
for  pumping  condensate,  circulating  water  and  feed  water. 

Centrifugal  pumps  should  have  the  impeller  designed  for  the  conditions  of  suction  head,  de- 
livery head,  sp'eed  and  capacity  the  pump  is  to  work  under.  Well  designed  pumps  give  efficiencies 
of  from  75  to  80  per  cent. 

The  centrifugal  pumps  of  five  stages  used  in  the  high  pressure  fire  service  in  the  City  of  New 
York  showed  under  test  efficiencies  of  75  and  77  per  cent  when  working  with  delivery  pressures 
of  300  Ibs. 

Centrifugals  are  sometimes  arranged  so  that  two  pumps  driven  by  the  same  shaft  may  deliver 
into  a  common  discharge,  thus  giving  a  large  quantity  at  a  moderate  pressure;  or  the  discharge 
of  one  may  be  sent  into  the  suction  of  the  other  and  the  delivery  pressure  increased ;  the  quantity 
of  water  being,  of  course,  decreased. 

If  the  efficiency  of  each  pump  is  71  per  cent  the  efficiency  of  the  outfit  used  either  way  will 
remain  practically  the  same. 

In  pumping  circulating  water  from  a  jet  condenser  to  a  cooling  tower,  as  there  is  less  than 
atmospheric  pressure  on  the  suction  side  of  the  pump,  the  total  static  head  should  be  calculated 
from  the  difference  of  the  absolute  pressures  at  entrance  to  and  exit  from  the  pump.  To  this  head 
expressed  in  feet  should  be  added  an  amount  sufficient  to  allow  for  the  friction  and  other  losses. 

The  efficiency  of  the  smaller  pumps  is  probably  not  over  60  per  cent. 

The  velocity  of  water  in  the  discharge  pipe  should  not  exceed  400  feet  per  minute;  6  feet  a 
second  is  a  velocity  quite  commonly  allowed. 

Although  a  number  of  centrifugal  pumps  connected  to  jet  condensers  may  work  successfully 
when  piped  to  a  common  discharge  leading  to  a  cooling  tower,  it  is  always  safer  to  connect  each 
centrifugal  with  the  tower  through  a  separate  pipe. 

Turbine  driven  stage  centrifugals  are  quite  generally  used  now  in  the  large  boiler  plants  in 
place  of  the  steam  or  power  driven  reciprocating  feed  pump.  The  hot  feed  water  must  come  to 
the  pump  under  a  head.  The  efficiency  of  centrifugals  used  as  feed  pumps  may  be  assumed  to  be 
between  40  and  55  per  cent ;  45  per  cent  has  been  used  as  the  efficiency  in  the  calculation  for  horse 
power  input  given  below. 

The  maximum  horse  power  input  required  by  a  centrifugal  boiler  feed  pump  is 

r,     ,  .f       ,  T-,  2.32  x  Gage  Pressure  x  30  x  Max.  Boiler  H.  P. 

Centnfugal  Feed  Pump  H.  P.  rnput  =  -  33,000  x  60  x  .45 

7.8  X  Gage  Pressure  X  Max.  Boiler  H.  P. 

approx. 


100,000 

Centrifugal  pumps  have  to  be  primed  (filled  with  water)  before  starting.  This  may  be  done  by 
putting  a  foot  valve  on  the  end  of  the  suction  pipe  and  then  filling  with  water  under  pressure,  the 
air  at  the  top  of  the  casing  being  vented,  or  the  pump  may  be  primed  by  closing  a  valve  in  the 
delivery  pipe  and  then  exhausting  air  from  the  top  of  the  pump  casing  by  a  steam  ejector,  a  water 
ejector  or  by  means  of  a  connection  to  a  dry  vacuum  pump. 

As  a  foot  valve  offers  considerable  resistance  to  the  flow  of  water  it  is  to  be  avoided  whenever 
possible;  should  it  be  necessary  to  use  a  foot  valve  one  at  least  two  sizes  larger  than  the  suction 
pipe  is  to  be  recommended. 

Centrifugal  pumps  of  large  capacity  either  turbine  driven  or  motor  driven  have  been  used  as 
pumping  units  in  municipal  pumping  stations.  While  it  is  not  possible  to  get  as  high  a  duty  as 
may  be  obtained  with  a  reciprocating  pump  the  first  cost  is  only  about  one  third  that  of  the  recip- 
rocating and  the  number  of  operatives  required  to  run  the  centrifugal  outfit  is  less. 

These  pumps  should  have  both  a  check  valve  and  a  hydraulically  operated  discharge  valve 
in  the  discharge  pipe.  In  shutting  the  pump  down  the  discharge  valve  is  closed  before  the  power 


NOTES  ON  POWER  PLANT  DESIGN  83 

is  shut  off.     While  the  pump  might  be  stopped  without  closing  this  valve  and  the  check 
pended  upon  to  prevent  a  flow-back  from  the  reservoir  or  standpipe,  should  this  valve 
and^dose  suddenly  the  water  hammer  blow  resulting  could  not  b^thstoodbythep 

Pumps  used  for  this  service  should  have  suitable  characteristics.     The  pressure  should  not 
build  up  over  15  per  cent  when  the  discharge  valve  is  closed  with  the  pump  mnnTng 

llowing  are  some  characteristic  curves  obtained  from  test  data  on  different  types  of  Dumos 

i^^t^^^ 

fo?  adlrvlTeTumpThlS  PUmP  "aS  n°  dbcharge  ™1VeS  and  *™  an  SC3w£Sfc&  £  Mgh 
Fig.  2  gives  the  curves  of  a  DeLaval  pump  which  are  notable  in  that  the  power  taken  bv  the 


piping  should  fail  while  the  pump  was  in  operation.  The  head  would,  of  course  fall  nearlv  to  zero 
and  the  discharge  would  go  up  rapidly.  The  horse  power  taken  from  the  motor  under  Tlfese  con- 
ditions woud  increase  rapidly  due  to  the  marked  decrease  in  efficiency.  In  this  set  of  curves  the 


t  is  dangerous  in  many  cases  to  allow  a  pump  to  be  started  without  priming  since  manv 


The  con,tn,P^  secofnf,  for  PU™P.S  "thout  lift  and  W  feet  per  second  for  pumps  with  lift 


accompanylng  print        represents  the  angle  of  entrance  of  the  impeller  and  v  theangl 

£  ftfiS»  thl^f*  °f  the  ShaPe  °f  the  WadeS  -  the  exit 
The  De  Laval  centrifugal  is  made  with  the  angle  at  exit  20°  with  the  tangent. 


84  NOTES  ON  POWER  PLANT  DESIGN 

In  order  to  estimate  the  loss  of  head  through  friction  in  piping  the  accompanying  chart  taken 
from  the  catalogue  of  the  De  Laval  Co.  is  quite  convenient  to  use. 

If  the  quantity  of  water  passing  through  the  pipe  and  the  size  of  the  pipe  are  known,  the  fric- 
tion head  in  1000  feet  length  of  pipe  is  found  by  laying  a  straight  edge  through  the  known  points 
of  the  scales  representing  capacity  and  size  of  pipe.  The  friction  head  is  then  read  off  on  the  third 
scale  at  the  point  of  intersection  between  the  straight  edge  and  this  scale. 

The  values  obtained  from  this  chart  are  based  upon  the  Hazen-Williams  formula: 

0.63  /fc\0.54  0.12 

v  =  cr      l-r-\      X  10 

where  v  is  the  velocity  in  feet  per  second,  r  is  the  hydraulic  radius  =  -  —-: in  feet,  h  the  fric- 
tion head  and  /  the  length  of  piping,  c  is  a  constant  depending  upon  the  roughness  of  the  pipe 
and  upon  the  hydraulic  radius. 

The  formula  can  also  be  written 

147.85      _Q_Y'852 
c    '     Xd2-63/ 


where  h  is,  as  before,  the  friction  head  in  feet  for  /  =  1000  ft.,  Q  is  the  water  quantity  in  gallons  per 
minute  and  d  is  the  diameter  of  pipe  in  inches. 

The  chart  is  based  upon  a  value  of  c  =  100,  which  is  mostly  used  and  considered  safe  for  ordin- 
ary conditions. 

1.852 

For  other  value  of  c  the  figure  obtained  from  the  chart  should  be  multiplied  by  K  =    -    - 


For  information  regarding  coefficient  c  for  different  kinds  and  size  of  pipes,  and  also  value  of 
K  for  different  values  of  c,  see  table  below. 


Size  of 
Pipe,  inches                                                    2  to  3 

4 

5 

6 

8 

10 

12 

16 

20 

24 

30 

36 

42 

48 

54 

60 

c 

K     Condition  of  pipe 

Year  of  Service  for  Cast  Iron  Pipe 

140 

.54   Very  smooth  and  straight 
and  Brass,  Tin,  etc. 

00 

00 

00 

00 

00 

00 

00 

00 

00 

00 

00 

00 

00 

00 

00 

130 

.615  Ordinary  straight  Brass  or  Tin 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

120 

.7  15  Smooth  new  Iron 

4 

4 

4 

5 

5 

K 
w 

5 

5 

5 

6 

6 

6 

6 

6 

6 

iio 

.84 

10 

10 

10 

11 

11 

11 

12 

12 

12 

12 

12 

12 

100 

1.0     Ordinary  Iron* 

13 

14 

15 

16 

17 

17 

18 

19 

19 

19 

20 

20 

20 

20 

20 

90 

1.21 

26 

27 

28 

29 

30 

30 

30 

30 

31 

31 

80 

1.51   Old  Iron 

26 

28 

30 

33 

35 

37 

39 

41 

42 

43 

44 

45 

45 

46 

47 

60 

2.58  Very  rough 

45 

50 

55 

62 

68 

40 

5.45   Badly  tuberculated 

75 

87 

95 

00  indicates  the  very  best  cast  iron  pipe  laid  perfectly  straight,  and  when  new. 
0  indicates  good  new  cast  iron  pipe. 


NOTES  ON  POWER  PLANT  DESIGN 


85 


F 


/So ooo 


— /oo ooo 
^—     3oooo 

—  60000 

—  70000 

—  60000 
-SOOOO 

—4OOOO 
-Joooo 


-  2oooo 
—  /Sooo 


—/OOOO 
9000 
Sooo 

"  7000 
6000 

—Sooo 


Sooo 


Zooo 


—  /Soo 


i 


_   300 

1—    7oo 
1—    600 

—  Soo 
4So 

—  400 

1-     3So 
—3  oo 


-/oo 

9o 

So 

7o 

60 
.50 


9o 

7S 
•72 

66 
.60 


C.I   — 

o,/S  — 
o.g  — 

0.3  — 

0.4  — 

o.S  - 
0.6 
0.7 


0.9  — 


/.s 


Jo 


-*+  ^ 


/S 


o 

o 


I 


S? 


* 


(0 


Go 
70 
go 

30 

fOO  — 


/So. 


3oo 


Chart  for  determining  resistance  of  pipes  to  flow  of  water. 


86 


NOTES  ON  POWER  PLANT  DESIGN 


/eo 


9          fooo        gooo       3000       4000        SDOO       fooo      fooo        8000       9000      seooo     ,&oo      /gooo      aooo      /+ooo     *roeo      /eooo 


NOTES  ON  POWER  PLANT  DESIGN 


87 


3KOO 


3400  jffOO 


88 


NOTES  ON  POWER  PLANT  DESIGN 


700 


$00 


500 


400 


300 


ZOO 


soo 


if 


/OQ 


ZOO 


3OQ 


300 


6OO 


700 


NOTES  ON  POWER  PLANT  DESIGN 


89 


/3oo      /*co      /sexy     /6oo 


90 


NOTES  ON  POWER  PLANT  DESIGN 


VL    =  Linear  ve/oc/fy  of  impeller  at  outer  edge. 
T/L    =       //  //        //          11         a  Inner       "    . 

VEA  ~  Abso/ufe   ve/oc/fy  at  entrance  (Taken  rad/a/). 
VRW=  Ve/oc/ty  of  wafer  re/af/ve   to  wheel. 
VAB  =  Absolute  exit  velocity  from  impeller. 

Radial  ve/ociiy  at  entrance    is  usually  "taken 
at  IS  f.p.s.  if  there  is  no  lift  and  IO  f.p.s.  if 
there  is  a  lift. 


NOTES  ON  POWER  PLANT  DESIGN 


91 


COAL  HANDLING,   GOAL  BUNKERS 

FLIGHT  CONVEYORS 

One  of  the  oldest  forms  which,  from  its  simplicity  and  comparatively  low  first  cost,  is  still 
one  of  the  most  extensively  used,  consists  merely  of  an  endless  chain  to  which  are  attached,  at  in- 
tervals, scrapers  or  flights.  The  improved  forms  of  this  conveyor,  now  most  generally  used,  have 
sliding  shoes  or  rollers  attached  to  the  flights  or  the  chains,  supported  on  runways.  The  flights  are 
allowed  to  come  very  close  to  the  trough  bottom,  but  not  actually  in  contact  with  it,  thus  reduc- 
ing the  friction  upon  the  trough  to  the  minimum  amount. 

The  accompanying  figure  illustrates  a  single-strand  flight  conveyor. 

CONVEYING   CAPACITIES   ON   FLIGHT  CONVEYORS 

S.  R.  Peck,  A.  S.  M.  E.,  1910 

In  tons  (2000  pounds)  of  coal  per  hour  at  100  feet  per  minute. 


Size 
of 

Flight 
4x10 
4x12 
5x12 
5x15 
6x18 
8x  18 
8x20 
8x24 
10x24 


18  Inches 
33% 


69% 


Horizontal 

Spaced 

18  Inches 

24  Inches 

30 

22^ 

38 

28)^ 

46 

34^ 

62 

46^ 

80 

60 

120 

90 

105 

135 

172^ 

Lbs.  per 
Flight 
15 
19 
23 
31 
40 
60 
70 
90 
115 


10° 
24  Inches 

24 

2sy2 


Inclined 


49^ 

72 

84 
120 
150 


20° 
24  Inches 

14% 

18 


24 


30° 

Inches 

10J* 


31}* 


22y2 


57 

66^ 
96 
120 


48 
56 
72 
90 


The  horse-power  required  for  handling  anthracite  coal  may  be  determined  from  the  follow- 
ing formula,  this  taking  no  account  of  gearing  or  other  driving  connections. 


H.  P.  = 


ATL  +  BWS 
1000 


T  =  net  tons  per  hour. 
L  =  length,  centre  to  centre,  in  feet. 
W  =  weight  of  chain  and  flights  (both  runs)  in  pounds. 
S  -  speed  per  minute  in  feet. 


92  NOTES  ON  POWER  PLANT  DESIGN 

A  and  B  are  constants  depending  on  the  inclination  from  the  horizontal.     (See  value   below.) 

Hor.        5°  10°  15°  20°  25°  30°          35°  40°          45° 

A        0  343      0.42        0.50        0.585      0.66        0.73        0.79        0.85        0.90        0.945 
B        0.01        0.01        0.01        0.01        0.009      0.009      0.009      0.008      0.008      0.007 

The  common  working  speeds  are  from  100  to  200  feet  per  minute,  and  the  capacities  are  as 
shown  by  the  table,  these  conveyors  in  some  cases  handling  upwards  of  500  tons  per  hour. 

As  an  illustration,  suppose  it  is  desired  to  elevate  hard  coal  50  feet  by  a  flight  conveyor  inclined 
30  degrees,  the  capacity  of  the  conveyor  being  30  tons  per  hour  at  100  feet  speed  per  minute.  From 
the  table  it  is  evident  that  at  a  speed  of  100  feet  per  minute  the  flight  should  be  6  inches  by  18  inches 
and  spaced  24  inches  apart. 

The  length  of  the  conveyor,  centre  to  centre,  would  be  at  least  100  feet. 

Calling  the  weight  of  the  chain  20  pounds  per  foot,  and  the  weight  of  the  flights  spaced  every 
2  feet,  40  pounds,  as  given,  the  total  weight  per  foot  figures  as  40  pounds. 

Substituting,  in  the  formula  given,  the 

0.79  x  30  x  100) +  (0.009  x  200  x  40  x  100) 
1000 

=  7.77 


PIVOTED  BUCKET  CARRIERS 

Where  the  design  of  the  plant  requires  convey  ing  machinery  adapted  to  the  combined  service 
of  handling  coal  and  ashes,  the  pivot-bucket  carrier  is  hard  to  excel.  The  handling  of  ashes  is  very 
hard  on  conveying  machinery,  and  the  construction  of  the  carrier  permits  replacement  of  the  several 
parts  as  corrosion  or  wear  proceeds. 

Pivoted-bucket  carriers  for  elevating  coal  in  power-plant  service  have  become  quite  popular. 
Their  advantages  are  slow  speed,  silent  operation,  adaptability  to  change  of  .direction  without 
transfer,  high  efficiency,  and  easy  renewal  of  worn  parts.  Their  disadvantages  are  danger  of  buckets 
sticking  or  upsetting  and  jamming  in  the  supports,  and  the  difficulty  of  preventing  spill  at  the 
loading  and  turning  .points.  Protection  against  jamming  may  be  had  by  connecting  with  the 
driving  machinery  through  a  safety  pin  whose  margin  of  strength  beyond  the  power  requirements 
is  very  slight ;  or  better,  by  designing  the  supports  so  that  the  buckets  will  clear  in  whatever  posi- 
tion they  may  come  around. 

Uncleanly  loading  is  guarded  against  in  various  ways  in  the  several  latest  designs  of  carriers, 
of  which  the  following  may  be  noted. 

In  the  Hunt  carrier,  the  buckets  are  spaced  an  inch  or  so  apart  and  are  loaded  by  a  special 
device  consisting  of  a  series  of  connected  funnels  at  the  loading  chute,  in  synchronism  with,  and 
dipping  into,  the  carrier  buckets,  so  that  each  bucket  receives  its  proper  charge  only. 

The  Webster  carrier  has  buckets  with  carefully  planed  lips,  the  pitch  of  the  buckets  being  very 
slightly  less  than  the  pitch  of  the  carrier  chain  links,  thus  depending  on  close  contact  to  eliminate 
the  leakage. 

The  McCaslin  carrier  uses  overlapping  buckets.  These  lap  the  wrong  way  after  tripping  for 
discharge,  and  are  reversed  by  a  "righting  mechanism"  before  again  passing  the  loading  point. 

The  Peck  carrier  uses  overlapping  buckets  similar  to  the  McCaslin,  but  they  are  attached 
to  the  links  extended  beyond  the  points  of  articulation.  This  arrangement  unlatches  the  buckets 
at  the  turns  by  giving  them  a  path  of  greater  radius  than  the  chain  joints,  thereby  doing  away  with 
a  righting  device  otherwise  necessary  with  the  overlapping  bucket. 

None  of  these  devices  for  preventing  spill  at  the  loading  and  turning  points  are  particularly 
effective.  The  difficulty  is  inherent  in  this  type  of  conveyor  whose  many  advantages,  however, 
far  outweigh  their  defects. 

The  alternative  of  the  pivoted-bucket  carrier  fof  handling  coal  is  the  standard  arrangement 
of  an  elevator  with  rigid  steel  buckets  discharging  into  a  flight  conveyor  which  crosses  above  the 


NOTES  ON  POWER  PLANT  DESIGN 


93 


bunkers,  and  is  provided  with  discharge  gates  at  convenient  intervals;  or  instead  of  a  flight  con- 
veyor, a  belt  with  movable  tripper.  This  is  a  well  tried-out  system,  thoroughly  reliable,  and 
by  many  preferred  to  the  run-around  carrier,  on  the  ground  of  lower  first  cost  and  simpler  con- 
struction. The  elevator  conveyor  system  is  not  adapted  to  handling  ashes,  which,  however,  should 
be  t:.ken  care  of  by  separate  machinery  whenever  possible  to  do  so. 


Diagram  Showing  Operation  of  the  Peck  Carrier 

The  general  arrangement  of  a  "rectangular"  pivoted  bucket  conveyor  is  shown  by  the  accom- 
panying cut. 

Coal  discharged  from  a  car  or  from  a  cart  falls  into  a  crusher  where  the  large  lumps  are  broken 
up.  From  the  crusher  the  coal  is  taken  directly  into  the  conveyor  or  into  the  feeding  mechanism' 
which  fills  the  conveyor. 

Somewhere  in  the  system  there  must  be  a  tightener,  which  in  this  cut  is  shown  as  located  at 
the  lower  right-hand  corner. 

_  The  reciprocating  feeder  consists  simply  of  a  movable  plate,  at  the  bottom  of  the  hopper, 
which  is  pushed  forward  and  back  through  the  action  of  an  eccentric.  On  the  forward  stroke 
coal  is  fed  into  the  crusher.  The  length  of  the  plate  is  such  that  coal  in  the  hopper  will  not  flow 
over  the  left-hand  edge  when  the  feeding  plate  is  still. 

When  coal  is  discharged  directly  through  the  track  hopper,  feeder  and  crusher  into  the  con- 
veyor buckets  as  shown  in  the  cut,  the  track  must  be  from  10  to  12  feet  above  the  bottom  run 
of  the  conveyor. 

Where  there  is  not  sufficient  depth  for  this  arrangement  an  apron  feeder  (see  illustration) 
would  be  used  to  elevate  the  coal  to  the  crusher. 

The  speed  of  the  apron  must  be  regulated  to  suit  the  capacity  of  the  carrier  or  a  reciprocat- 
ing feeder  may  be  inserted  between  the  hopper  and  the  apron. 


94 


NOTES  ON  POWER  PLANT  DESIGN 


STANDARD   SIZES  AND   CAPACITIES   OF  PECK   CARRIERS 

For  a  speed  of  from  40  to  50  feet  per  minute  with  pitch  of  chain  24  inches  the  capacity  is 
with  buckets  24"  x  18"  40  to  50  tons  coal  per  hour 

with  buckets  24"  x  24"  55  to  70  tons  coal  per  hour 

with  buckets  24"  x  30"  75  to  100  tons  coal  per  hour 

with  buckets  .          24"  x  36"  90  to  120  tons  coal  per  hour 


TM    »  CLUMMCt          /     s~ 
General  Dimensions, 
«-"i"      (  (tjT^  '  -  -'-  -"1>         24-inch  Pitch  Carriers 


General  Dimensions,  24-inch  Pitch  Carriers 

ClCARAUCe  FOB  DUMPING  I 


General  Dimensions,  24- inch  Pitch  Carriers 


DIMENSIONS  CHANCING  WITH  WIDTH  OF  BUCKETS 

"iftP 

E 

27" 
30" 
33" 
36" 

G 

48" 
51" 
54" 

57" 

H 

) 

5U" 

571" 
63t" 
69J" 

K 

50J" 

5«i" 

62J" 
68J" 

L 

24,18 
24x24 
24.3O 
24,36 

66" 
72" 
78" 
84" 

534" 
561" 
59j" 
62  " 

DIMENSIONS  CHANCING  WITH  WIDTH  OF  BUCKETS 

X 

y 

Z 

SuxL 

Mm. 

Slud. 

Mm. 

M.nJ 

Mil. 

531" 

33" 

7'-0" 

y-6" 

lO'-O" 

56|" 

7'-ff" 

5'-6" 

10'-0" 

9'-0" 

62»" 

42" 

7'-0" 

5'-6" 
5'-6" 

lO'-O" 
10'.0" 

9'-0" 
V-0" 

Plan  View,  Lower  Corner 


Plan  View 


NOTES  ON  POWER  PLANT  DESIGN 


95 


The  general  dimensions  of  a  Peck  carrier  24"  pitch  may  be  obtained  from  the  cuts  shown  on 
the  preceeding  page. 

The  power  required  for  driving  a  rectangular  conveyor  similar  to  those  referred  to  may  be 
obtained  from  the  following  formula  which  is  based  on  tests  made  on  a  number  of  such  conveyors. 
H.  P.  =  .000085  x  tons  per  hour  x  speed  in  feet  per  minute  X  elevation  in  feet.  The  power  run- 
ning empty  is  approximately  one-half  of  the  power  for  loaded  condition.  The  power  required 
for  an  apron  feeder  may  be  calculated  from  the  same  formula.  A  reciprocating  feeder  requires 
about  5  H.  P. 


A  coal  crusher  of  30  tons  capacity  per  hour  requires  a  floor  space  of  7'  X  4 '-6"  and  height  of 
3  feet  overall  when  set  on  a  cast  iron  base  and  2  feet  when  set  as  shown  in  the  cut  illustrating  the 
apron  feeder.  It  requires  5  H.  P.  to  drive  it. 

A  50  ton  crusher  10  H.  P.  with  floor  space  9'  x  5'  and  heights  of  3'  6"  and  2'  6"  according  to 
setting. 


A  70  ton  crusher  15  H.  P.  space  9'  x  6'  and  heights  of  4'  6"  and  3'  6". 
The  accompanying  cut  shows  a  crusher  with  hopper  and  casing  removed. 
A  V  bucket  elevator  conveyor  is  shown  by  the  sketch  on  the  page  following, 
diagrams  A-F  indicate  some  of  the  possible  arrangements. 


The  small 


96 


NOTES  ON  POWER  FLA  XT  DESIGN 


Coal  is  fed  to  the  lower  run  by  a  plain  chute,  is  then  pushed  along  the  run  till  the  vertical  is 
reached,  where  the  coal  is  carried  inside  the  buckets;  on  the  upper  run  the  coal  is  pushed  along 
until  it  reaches  an  opening  through  which  it  is  discharged. 

A  40  ton  V  bucket  elevator  installed  at  the  Bergner  and  Engel  Brewing  Co.'s  plant  and  a 
40  ton  coal  elevator  and  flight  conveyor  at  the  U.  S.  Arsenal  at  Frankford  are  shown  by  the  cuts 
which  follow. 


U.  S.  ARSENAL.  FRANKFORD,  PHILA. 


NOTES  ON  POWER  PLANT  DESIGN 


97 


A  locomotive  crane  operating  a  grab  bucket  is  frequently  used  to  move  eoal  from  a  storage 
pile  onto  a  belt  or  bucket  conveyor,  for  unloading  barges,  etc. 


oo8> 


BERGNER  AND  ENGEL  BREWING  Co.,  PHILADELPHIA,  PA. 
40  ton  per  hour  v-bucket  elevator.     Conveyor  for  coal ;  push  car  and  electric  skip  for  ashes. 


Such  cranes  are  either  mounted  on  a  car  like  a' platform  car  or  elevated  as  shown  by  the  accom- 
panying figure. 

For  unloading  barges  and  hoisting  coal  to  an  elevator  a  tower  known  as  the  Boston  tower 
is  quite  generally  used.  This  handling  device  consists  of  a  grab  bucket  operated  from  the  tower, 
which  has  projecting  out  a  distance  of  20  or  30  feet,  a  horizontal  arm  on  which  travels  a  movable 
carriage  through  which  run  the  hoisting  ropes  operating  the  grab  bucket.  This  carriage  rray 
be  moved  out  or  in  while  the  grab  is  being  raised  or  lowered. 


98  NOTES  ON  POWER  PLANT  DESIGN 

BELT    CONVEYORS 

If  coal  is  to  be  conveyed  any  considerable  distance  a  belt  conveyor  would  be  used.  Belt  con- 
veyors will  carry  coal  at  an  angle  as  great  as  20°  and  may  be  built  to  handle  any  quantity  of  coal. 

The  following  table  gives  the  capacity,  maximum  size  of  lumps,  and  advisable  speed  for  the 
different  widths  of  belts. 

BELT  CAPACITY   AND   SPEED 

Capacity  in  Cubic 

Maximum  Advis-  Feet  at  the  Maxi- 

Width  of                  Maximum  Size        able  Speed  in  mum  Advisable 

Belt.                         of  Pieces.          Feet  per  Minute.  Belt  Speed. 

12                                 2                               300  1380 

14                                 21A                           300  1890 

16                                 3                               300  2460 

18                                 4                               350  3640 

20                                5                               350  4480 

22  6  400  6200 

24  8  400  7400 

26  9  450  9810 

28  12  450  11250 

30  14  450  13050 

32  15  500  16500 

34  16  500  18500 

36  18  500  21000 

38  19  550  25300 

40  20  550  28050 

42  20  550  30800 

44  22  600  37200 

•    46  22  600  40800 

48  24  600  44400 

When  the  quantity  to  be  conveyed  is  small,  and  the  pieces  large,  the  size  of  the  material 
fixes  the  width  of  the  belt,  and  the  speed  should  be  as  low  as  possible  to  carry  safely  the  desired 
load. 

When  the  quantity  is  great,  the  capacity  fixes  the  width,  and  in  this  case  also,  the  speed  should 
be  as  low  as  possible.  A  belt  at  slow  speed  may  be  loaded  more  deeply  than  one  at  high  speed , 
and  when  a  narrow  belt  is  run  much  above  the  advisable  speed,  the  load  thins  out  and  the  capacity 
does  not  increase  as  the  speed. 

The  maximum  length  of  the  different  widths  of  conveyors  is  determined  by  the  fibre  stress 
in  the  belt,  and  is,  therefore,  closely  related  to  the  load  and  speed.  Naturally  level  conveyors 
may  be  built  longer  than  those  lifting  material.  Conveyors  1000  feet  from  centre  to  centre,  hand- 
ling 400  tons  per  hour,  have  been  most  satisfactorily  operated. 

Another  important  factor  in  the  design  of  conveyors  operated  at  highspeed  and  handling  large 
quantities  is  the  flow  of  material  in  the  chutes.  A  36-inch  conveyor  handling  750  tons  of  coal  per  hour, 
with  a  belt  speed  of  750  feet  per  minute  under  a  10,000ton  pocket,  could  not  be  loaded  from  a  single 
chute,  because  it  was  not  possible  for  the  coal  to  attain  a  speed  of  750  feet  per  minute  in  the  chute. 
It  was  necessary,  therefore,  in  order  to  obtain  a  full  load,  to  open  seven  gates,  each  placing  a  layer 
of  coal  on  the  belt  until  the  desired  load  was  obtained.  During  a  test  this  belt  carried  about  800 
tons  per  hour. 


NOTES  ON  POWER  PLANT  DESIGN  99 

x 

POWER  REQUIRED   FOR  BELT  CONVEYORS 

The  power  required  to  drive  a  belt  conveyor  depends  on  a  great  variety  of  conditions,  such 
as  the  spacing  of  idlers,  type  of  drive,  thickness  of  belt,  etc. 

_  In  figuring  the  power  required,  it  is  important  to  remember  that  the  belt  should  be  run  no  faster 
than  is  required  to  carry  the  desired  load.  If  for  any  reason  it  is  necessary  to  increase  the  speed, 
the  hgure  taken  for  load  should  be  increased  in  proportion  and  the  power  figured  accordingly 

follows61  W  P°Wer  alWayS  be  figUred  f°r  the  fuU  capacity  at  the  chosen  speed,  as 


C  =  power  constant  from  table. 
T  =  load  in  tons  per  hour. 
L  =  length  of  conveyor  between  centres  in  feet. 
H  =  vertical  height  in  feet  that  material  is  lifted. 
S  =  belt  speed  in  feet  per  minute. 
B  =  width  of  belt  in  inches. 
For  level  conveyors, 

TT  p       C  x  T  x  L 

~Toob~ 

For  inclined  conveyors, 

H  P  =  CxTxL      TxH 
1000  1000 

Add  for  each  movable  or  fixed  tripper  horse-power  in  column  3  of  table  below. 

Add  20  per  cent  to  horse-power  for  each  conveyor  under  50  feet  in  length. 

Add  10  per  cent  to  horse-power  for  each  conveyor  between  50  feet  and  100  feet  in  length 

I  he  above  figures  do  not  include  gear  friction,  should  the  conveyor  be  driven  by  gears. 

POWER  REQUIRED  FOR  GIVEN  LOAD 

1234 
C  H.  P. 

Fcr  Material  For  Material  Required  for 

THT.UI.  ^g£ing*fr2!P          Weighing  from  Each  Movable  Minimum  Maximum 

Width  25  Ibs.  to  75  75  Ibs.  to  125         or  Fixed  Tripper  Plies  of  Plies  of 

Bdt.  &.£  !£T  Belt'  ^.t. 

12  .234  .147                            y»  3  4 

14  .226  .143 

16  .220  .140  & 

18  .209  .138  1 

20  .205  .136  1M  4                                6 

22  .199  .133  \%  5                              g 

24  .195  .131  1%  5                               7 

26  .187  .127  2  7 

28  .175  .121  2&  8 

30  .167  .117  Q 

32  .163  .115  2K  9 

34  .161  .114  3  6                             10 

36  -157  .112  3^  6                             10 

With  the  load  and  size  of  material  known,  choose  from  the  capacity  table  the  proper  width 
ot  belt  and  proper  speed.  The  above  formulae  give  the  horse-power  required  for  the  conveyor 
when  handling  the  given  load  at  the  proper  speed.  With  the  horse-power  and  the  speed  known 
the  stress  m  the  belt  should  be  figured  by  the  following  formula  in  order  to  find  the  proper  number 
of  plies. 


100  NOTES  ON  POWER  PLANT  DESIGN 

H.  P.  X  33000 
Stress  in  belt  in  pounds  per  inch  of  width  =         $  v  B — 

With  this  value  known,  the  number  of  plies  may  be  determined,  using  20  pounds  per  inch 
per  ply  as  the  maximum.  Columns  4  and  5  of  this  table  give  the  maximum  and  minimum  advisable 
plies  of  the  different  widths  of  belt.  Belts  between  these  limits  will  trough  properly  and  will  be 
stiff  enough  to  support  the  load. 

Belt  conveyors  may  be  driven  from  either  end.  Somewhere  in  the  system  there  must  be  a 
tightener  to  allow  for  the  stretch  of  the  belt.  The  troughing  idlers  should  be  placed  dependent 
upon  the  weight  of  material  carried  as  follows: 

For  belts  12  to  16  inches  wide,  from  4^  to  5  feet  apart; 
For  belts  18  to  22  inches  wide,  from  4  to  4 Y^  feet  apart; 
For  belts  24  to  30  inches  wide,  from  3^  to  4  feet  apart,  and 
For  belts  30  to  36  inches  wide,  from  3  to  3]/2  feet  apart. 

The  life  of  the  belt  depends  a  great  deal  upon  the  care  which  it  receives,  upon  the  material 
handled,  and  upon  the  quality  of  the  belt  to  begin  with.  In  general  the  life  of  the  belt  may  be 
taken  as  from  three  to  eight  years. 

THE  DARLEY  CONVEYOR 

A  system  for  handling  coal  or  ash  by  a  current  of  air  flowing  in  a  pipe  has  been  in  use  in 
some  plants  during  the  last  three  years.  A  description  of  a  system  arranged  for  handling  ash 
will  show  the  method  of  operation.  A  pipe  is  laid  under  the  floor  in  front  of  the  boilers  with  an 
opening  through  the  floor  into  the  pipe  in  front  of  each  ash-pit  door,  each  opening  being  closed 
unless  ash  is  being  hauled  from  the  ash-pit  into  it.  The  end  of  the  pipe  under  the  floor  is  open 
to  the  air.  The  other  end  of  this  pipe  connects  with  a,  riser  which  leads  up  to  the  top  of  a  closed 
steel  storage  tank  in  which  the  ash  is  to  be  stored.  An  exhaust  fan  or  a  Root  exhauster  draws  air 
out  of  the  tank,  thus  creating  a  flow  in  the  pipe  in  front  of  the  boilers.  Any  ashes,  clinker,  or  even 
bricks  dumped  in  through  the  holes  in  front  of  the  boilers  will  be  carried  along  by  the  air  and 
delivered  into  the  closed  tank  elevated  20  to  40  feet  above  the  boilers.  After  the  exhauster  has 
been  stopped  the  ashes  may  be  discharged  from  this  tank  into  a  car  or  cart  by  opening  an  ash 
valve  in  the  bottom. 

To  quench  the  hot  ash  and  to  prevent  dust  from  being  drawn  over  into  the  exhauster,  a  jet 
of  water  is  sent  in  on  the  ash  as  it  is  entering  the  closed  tank. 

The  fittings,  especially  those  at  the  corners  where  the  direction  changes  wear  rapidly.  The 
elbows  are  made  with  renewable  chilled  backs  or  in  some  cases  a  tee  is  used  in  place  of  an  elbow. 
The  plugged  end  of  the  tee  filling  up  with  ash  causes  the  wear  to  come  on  the  ash. 


COAL  BUNKERS 

Coal  bunkers  may  be  of  the  cylindrical  type  with  conical  bottom ;  of  the  parabolic  type  made 
either  of  steel  plate  lined  or  unlined  with  concrete  or  of  suspended  steel  straps  with  reinforced 
concrete  carrying  the  load  between  the  straps,  of  the  structural  steel  type  carried  on  girders 
running  either  parallel  with  the  boiler  fronts  or  on  cross  girders  at  right  angles  to  the  boiler 
fronts;  the  steel  being  protected  by  a  reinforced  concrete  lining. 

It  is  difficult  to  make  a  calculation  of  the  stresses  in  the  girders  supporting  a  coal  bunker, 
1st,  on  account  of  the  unequal  and  variable  loading  and  2nd,  because  the  coal  may  act  like  a  dry 
sand  under  certain  conditions  and  again  under  other  conditions  like  moist  earth.  A  treatise  on 
walls,  bins  and  grain  elevators  by  Ketchum  contains  the  best  information  available  on  this  subject. 

The  parabolic  type  of  bunker  is  easy  to  construct  and  brings  no  eccentric  load  of  any  mag- 
nitude to  the  columns  carrying  it. 


101 


A  simple  method  of  drawing  a  parabolic  for  any  sag  and  span'  is  -'gndwn  bytne  iilusirafion. 
The  actual  curve  is  slightly  different  from  a  parabola.     The  coal  may  be  heaped  from  the 
edges  towards  the  centre  of  the  span  at  an  angle  depending  upon  the  angle  of  repose  of  coal  which 
is  from  35°  to  40°. 

If  D  =  the  depth  of  the  curve 
S  =  the  span 

C  =  the  capacity  per  foot  of  length 
X  =  zero  at  the  lowest  point  of  the  curve. 

The  correct  equation  becomes 


S 


The  capacity  when  filled  level  full  is  per  foot  of  length  C  =  '.625  DS. 

The  supporting  forces,  the  thrust  brought  to  the  compression  members  placed  between  the 
columns  at  the  top  and  the  tension  in  the  upper  ends  of  the  plate,  may  be  found  graphically.  The 
total  horizontal  tension  in  the  plate  at  the  bottom  is  the  same  as  the  total  compression  carried 
to  the  compression  members  at  the  top. 

A  parabolic  pocket  known  as  the  Brown  is  constructed  of  steel  straps,  bent  to  the  correct 
shape,  riveted  at  either  end  to  channel  bars  attached  to  the  columns.  These  straps  carry  the  load 
and  are  spaced  from  3  feet  to  4  feet  10  inches  according  to  the  weight  to  be  carried.  On  these  straps 


a  special  crimped  steel  sheet  known  as  "ferro-inclave"  is  laid  as  a  reinforcing  material  and  a 
thickness  of  concrete  from  2"  to  .4"  plastered  over  the  inside  and  a  similar  but  thinner  coating 
on  the  outside. 

A  section  of  "  ferro-inclave"  drawn  full  size  is  shown. 

Where  the  coal  valves  are  attached,  a  piece  of  steel  plate  is  fastened  to  the  straps  as  shown 
by  the  illustration. 

The  "Baker"  suspension  type  has  a  rigid  bottom  carried  by  suspension  rods  spaced  longitudin- 
ally at  such  distances  as  the  load  warrants.  Between  the  suspension  rods  unit  reinforced  concrete 
slabs  having  rounded  ends  form  the  sides  of  the  bin.  The  bottom  may  be  constructed  as  shown 
or  made  up  of  unit  slabs  like  the  side. 

This  method  of  constructing  the  sides  allows  of  a  bending  of  the  rods,  due  to  the  loading  of 
the  pocket,  without  cracking  the  lining. 


102 


NOTES  ON  POWER  PLANT  DESIGN 


.  -  - 


NOTES  ON  POWER  PLANT  DESIGN 


103 


UNIT  CONCRETE  SLAB  BIN. 
"  BAKER  "  SUSPENSION  TYPE. 

Coal  may  be  taken  from  the  coal  pocket  overhead 
into  a  weighing  hopper  and  from  this  discharged  to 
the  stoker  through  a  spout  in  front  of  each  boiler. 
The  end  of  the  spout  is  frequently  spread  out  fan  like 
and  known  as  a  spreader.  The  nozzle  type  is  preferable 
however. 

The  cut  shows  a  spout  with  nozzle  and  with  a  swivel 
or  universal  joint  at  the  top.  The  fireman  by  means 
of  the  handle  directs  the  coal  to  any  part  of  the  stoker 
reservoir  and  fills  same  evenly. 

•  Movable  weighing  hoppers  of  capacity  up  to  one 
ton  may  be  installed  and  operated  from  the  floor 
in  plants  of  moderate  size  (see  illustration). 

In  large  plants  a  motor  driven  crane  carries  a  weigh- 
ing hopper  of  larger  size  which  travels  under  the  coi  1 
pocket  over  the  firing  aisle  and  automatically  records 
the  weight  of  coal  fed  to  each  stoker. 


104 


NOTES  ON  POWER  PLANT  DESIGN 


LfeT 


I 


NOTES  ON  POWER  PLANT  DESIGN 


10- 


Cuts  of  two  different  weighing  hoppers  and  a  number  of  coal  valves  taken  from  Steam  Boilers 
are  given. 

Volume  of  Ton  of  Coal  Cu.  Ft. 

Soft  coal  ....  41  to  43 


Buckwheat  or  Pea 

Nut  ... 

Furnace  Size 

Coke 

Ash  dry  not  packed    . 


37 
34 
36 
76 

48  to  50 


106  NOTES  ON  POWER  PLANT  DESIGN 

FOUNDATIONS 
CONCRETE  FLOORS,  WALLS,  ETC. 

The  type  of  foundation  used  will  depend  upon  the  character  of  the  soil  and  upon  the  load 
to  be  brought  to  the  soil. 

Baker  in  his  Masonry  Construction  gives  the  following  safe  bearing  loads  of  soils.     These 
values  have  been  generally  accepted. 

Tons  per  sq.  ft. 

Min.  Max. 

Clay  in  thick  beds  always  dry      ......         6  8 

Clay  in  thick  beds  moderately  dry        .....         4  6 

Clay  soft 1  2 

Gravel  and  coarse  sand  well  cemented            .          .          .          .8  10 

Sand  dry,  compact,  well  cemented        .....         4  6 

Sand  clean  dry  .........         2  4 

Quicksand,  Alluvial  soils     .......        .5  1 

If  the  footing  is  spread  sufficiently  so  that  the  load  is  carried  by  the  soil  it  is  customary  to 
decrease  the  cross  section  of  the  footing  as  the  depth  decreases. 


With  a  1-2-4  concrete  the  allowable  offset  0  is  for  a  pressure  on  the  soil  of  .5  ton  per  sq.  ft 
I. It,  for  a  load  of  1  ton  .8*  and  for  a  load  of  2  tons  .5t  where  t  is  the  thickness  of  the  lower  section 
of  the  footing. 

In  many  cases,  especially  where  the  load  coming  to  the  footing  is  not  the  same  per  foot,  as 
for  example  in  the  setting  of  a  water  tube  boiler,  it  is  customary  to  reinforce  the  footing  with  steel 
rods  or  with  steel  beams  buried  in  the  concrete. 

If  the  land  on  which  the  structure  is  to  be  built,  is  made  land,  it  will  probably  be  necessary 
to  put  in  piles  to  support  the  footing. 

The  piles  may  be  either  wooden  or  concrete.  The  wooden  piles  cost  for  oak  20  to  30  feet 
long  6"  top  12"  butt  17  cents  per  foot  of  length;  oak  40  to  60  feet  long,  21  to  25  cents  per  foot  of 
length;  spruce,  20  to  30  feet  15  cents  per  foot  of  length. 

The  cost  of  driving  a  pile  and  cutting  off  is  about  9  cents  a  foot. 

Concrete  piles  cost  about  $20  for  a  40  foot  length  as  against  $9.50  for  wooden  piles;  the  bear- 
ing power  of  a  concrete  pile  is  however  2.5  tunes  that  of  a  wooden  pile. 

Wooden  piles  should  not  be  driven  closer  than  30"  on  centers. 

The  safe  bearing  load  of  a  wooden  pile  may  be  figured  with  more  or  less  uncertainty  by  what 
is  known  as  the  Wellington  or  the  Engineering  News  formula : 

P  =  safe  load  in  Ibs.  (factor  of  six  used) 
M  =  weight  of  drop  hammer  in  Ibs. 

h  =  fall  of  hammer  in  ft. 

s  =  penetration  or  sinking  in  inches  at  last  blow.     This  to  be  measured  when  there  is 
no  appreciable  rebound  of  the  hammer  and  the  head  of  the  pile  is  not  broomed. 


NOTES  ON  POWER  PLANT  DESIGN  107 

If  there  is  a  rebound  the  drop  of  hammer  should  be  reduced. 

2Mh 

;TTT 

Illustration 

Hammer  =  3000  Ibs. 

Drop  in  ft.  =  10  p  =  15,000  Ibs. 

Penetration  =  3" 


BRICKS 

A  mason  and  laborer  will  lay  1000  to  1500  bricks  per  day  in  a  wall  averaging  10"  to  12"  thick. 
The  cost  of  labor  per  1000  bricks  laid,  including  mason  and  helper  and  cost  of  erecting  stagings 
is  from  $8.00  to  $8.50. 

Bricks  cost  from  $7.50  to  $10.00  per  1000  and  a  thousand  bricks  will  lay  about  2  cubic  yards 
of  masonry. 

It  takes  about  20  bricks  8  34"  x  4"  x  234"  Per  cubic  foot;  the  masonry  weighing  125  Ibs.  per 
cu.  ft. 

In  a  power  house  the  floors  are  usually  of  reinforced  concrete  on  steel  beams.  The  boiler  room 
floor  is  generally  figured  for  250  Ibs.  live  load  and  the  engine  or  turbine  room  for  400  Ibs.  live  load. 

The  dead  load  of  various  types  of  floors  may  be  estimated  from  the  following  approximate  data : 
the  weights  are  given  per  sq.  ft.  of  surface. 

Wooden  wearing  surface      .....  4  Ibs.  per  inch  thick 

Granolithic  finish 12  Ibs.  per  inch  thick 

Cinder  filling      .......  5  Ibs.  per  inch  thick 

Stone  concrete  ........  12*/£  Ibs.  per  inch  thick 

Cinder  concrete          ......  9  Ibs.  per  inch  thick 

Plaster,  2  coats 5  Ibs.  per  inch  thick 

The  dead  load  of  any  roof  may  be  estimated  from  the  following: 

5  ply  felt  and  gravel  roofing         .         .  6  Ibs. 

3  ply  ready  roofing     .........         1  lb. 

Slate  3/16  thick 7^  Ibs. 

Clay  tile  ...  .  ...  12  Ibs. 

Tin  roofing •  11°. 

Copper  roofing  ......  2  Ibs. 

Corrogated  iron          .....  •  3  Ibs. 

Dry  cinders        ......••••*  Ibs. 

The  minimum  live  loads,  for  roofs  pitching  less  than  20°  vary  from  30  to  50  Ibs.  per  sq.  ft. 
according  to  different  City  Bldg.  Laws. 

For  a  pitch  greater  than  20°,  25  to  30  Ibs.  should  be  used. 

For  light  floor  loads  a  1-3-6  concrete  might  be  used.  This  mixture  might  also  be  used  in 
walls  carrying  but  small  loads.  For  heavy  loads  or  for  columns  a  1-2-4  or  richer  mixture  would  be 
used. 


108  NOTES  ON  POWER  PLANT  DESIGN 


REINFORCED  CONCRETE  FLOORS 

Various  types  of  reinforcing  rods,  woven  wire  fabric,  welded  wire  fabric  and  expanded  metal 
are  used  as  reinforcing  material  in  concrete  floors.  The  woven  fabrics  and  the  expanded  metal 
are  made  in  certain  definite  sections  and  from  tests  which  have  been  made  on  slabs  of  different  thick- 
ness, the  makers  of  the  various  reinforcing  fabrics  have  constructed  tables  some  of  which  have 
been  given  in  these  pages. 

While  tables  might  have  been  given  for  the  strength  of  slabs  reinforced  by  rods  of  one  type 
or  another,  it  was  felt  that  one  had  better  make  his  own  calculations  for  such  cases. 

The  formulae  generally  given  for  figuring  reinforced  concrete  beams  and  slabs  are  derived  on 
the  assumption  that  (1)  the  tensile  resistance  of  the  concrete  may  be  neglected  and  (2)  that  the 
stress  diagram  for  the  concrete  is  a  straight  line  up  to  the  safe  compressive  strength  of  the  concrete. 

Th'e  formulae  and  notation  given  below  are  practically  as  given  in  Turneaure  and  Maurer's 
Principles  of  Reinforced  Concrete  Construction.  See  also  Baker's  Treatise  on  Masonry  Construc- 
tion, Report  of  Joint  Committees  of  Engineering  Societies  and  Taylor  &  Thompson's  Reinforced 
Concrete. 

fs  =  fibre  stress  in  steel  per  sq.  inch  taken  as  16  to  18,000  Ibs. 

fc  =  fibre  stress  in  concrete,  the  maximum" compression  per  square  inch  at  outer  face;  for  1-2-4 

stone  concrete  from  600  to  700  Ibs.;  for  1-2-4  cinder  concrete  from  300  to  400  Ibs. 
Es  =  elongation  of  steel  per  inch  of  length  due  to  stress  fs  per  sq.  inch. 
EC  =  shortening  per  inch  of  length  of  the  concrete  due  to  the  stress  fc  per  sq.  inch. 
Es  =  modulus  of  elasticity  of  steel. 
EC  =  modulus  of  elasticity  of  concrete  in  compression. 

F 
n  =  -pr  generally  taken  as  15  for  1-2-4  stone  concrete  and  as  30  for  1-2-4  cinder  concrete. 

&c 

T  —  total  tension  in  the  steel  at  any  section  of  the  beam. 
C  =  total  compression  in  the  concrete  at  any  section. 
Ms  =  resisting  moment  as  determined  by  the  steel ;  inch  Ibs. 
Mc  =  resisting  moment  as  determined  by  the  concrete;  inch  Ibs. 
M  =  bending  moment  or  resisting  moment  in  general;  inch  Ibs. 
b  =  breadth  of  rectangular  beam  or  slab  in  inches. 

d  =  distance  in  inches  from  the  compressive  face  of  the  concrete  to  the  plane  of  the  steel. 
K  =  ratio  of  the  depth  of  the  neutral  axis  of  a  section  below  the  top,  to  the  distance  d,  generally 

taken  as  .375. 

j  =  ratio  of  the  arm  of  the  resisting  couple  to  the  distance  d. 
A  =  area  of  cross  section  of  the  steel. 

A 

P  =  -r-7-  =  the  steel  ratio  generally  from  .007  for  a  1-2-4  cinder  concrete  to  .0122  for  a  1-2-4 
stone  concrete. 

Since  cross  sections  that  were  plane  before  bending  remain  plane  after  bending  the  unit  defor- 
mations of  the  fibres  vary  as  their  distances  from  the  neutral  axis. 

E8       d-Kd  p       /L.  F      Js 

Wc  "        Kd~  ^ -  Ea'  c  ~  Ec 


Es     Js    _Ec  =  nJL       d-Kd  -K 

Ec~  ESX  fc~  fc  Kd  K 


NOTES  ON  POWER  PLANT  DESIGN 
as  the  total  tension  equals  the  total  compression 


f8Pbd=y2fcbdK; 


A 

Jc 


but  -f  = 

Jc 


K 


n  —  n  K 
~K~ 


P^1AK 


K2  +  2  Pn  K  +  (Pn)2  =  2  Pn  +  (Pn)2 
K  +  Pn  =  V2Pn  +  (Pn)2 

pi 
from  which  K  may  be  found  as  soon  as  the  steel  ratio  is  known  and  the  ratio  of  -^ 


108 


j  d  =  d  - 
If  A'  =  0.375 


j  =  1  -  yz  K 

j  =  0.872  or  about 


A  value  of  j  =  .85  is  used  by  some  designers  on  both  cinder  and  stone  concrete  of  1-2-4  mixture 


Mc=Cjd=  Y2fcb  Kdjd=  y2fc  Kjbd* 
The  fibre  stress  in  the  steel  for  a  given  bending  moment  is  equal  to 

_M_        _M_ 

•'*"   A  jd~  Pjbd* 


The  fibre  stress  in  the  concrete  fe  =      —      equating  values  of  M; 


f       2/*P. 

;«-    K    , 


2  M 

fcKj 


M 


110  NOTES  ON  POWER  PLANT  DESIGN 

W  I2 
The  bending  moment  for  beams  and  for  slabs  continuous  over  the  supports  is  M  =—  •—    where  W 

L£ 

is  the  load  per  inch  of  length  and  /  is  the  length  in  inches.     If  continuous  over  one  support  only 

W  I2  '  W  I2 

M  =  —  —  while  if  freely  supported  M  =  —  — 
ID  o 

If  a  rectangular  slab  be  reinforced  in  two  directions  the  bending  moment  would,  for  a  square 

W  /2 
panel  where  one-half  the  load  would  be  carried  in  each  direction,  be  M  =  —577-,   where   W    is    the 

*ni 

total  load  per  square  inch. 

For  a  rectangular  panel  the  proportion  of  the  load  carried  by  the  reinforcement  placed  the 

Z4 
short  way  of  the  span  is  r  =  —^  —  p 

r  W  I2 
The  reinforcement  for  the  short  span  is  then  figured  taking  as  the  bending  moment  —  ^  — 

(I  —  r)  W  I2 
and  in  a  similar  way  the  reinforcement  for  the  long  span  by  using  a  value  of  M  =  -  ^  -  . 

The  distance  from  the  center  of  the  reinforcing  bars  to  the  bottom  of  the  floor  slab  should  be 
1";  the  distance  between  centers  of  adjacent  bars  at  least  2^  diameters. 

The  distance  from  the  side  of  a  beam  or  slab  to  the  center  of  the  outer  bar  should  be  about 
2  diameters  of  bar. 

The  bearing  pressure  per  square  inch  where  a  slab  rests  on  its  supports  is  not  to  exceed  650 
Ibs.  per  sq.  inch. 

Concrete  beams  sometimes  fail  through  diagonal  tension;  floor  slabs  seldom  fail  in  this  way. 
A  beam  or  slab  may  be  made  safe  against  such  failure  by  keeping  the  average  shear  on  a  concrete 
having  a  compressive  strength  at  28  days  of  2000  Ibs.,  under  40  Ibs.  per  sq.  in.  in  cases  where  the 
horizontal  reinforcing  steel  is  not  bent  so  as  to  offer  help  in  resisting  diagonal  tension:  where  the 
reinforcing  material  is  bent  so  that  it  does  offer  help  the  average  shear  may  be  taken  as  60  Ibs. 
per  sq.  in.;  where  ample  reinforcement  for  resisting  diagonal  tension  is  specially  provided,  the 
average  shear  in  the  concrete  may  be  taken  as  120  Ibs.  per  sq.  in. 

As  the  horizontal  and  the  vertical  shear  are  of  the  same  intensity,  the  unit  shear  may  be 

Vertical  'shear  on  Section 
expressed  as  = 

bjd 

j  may  be  taken  as  .85  or  .87. 

In  finding  the  area  of  reinforcing  steel  (A8)  necessary  for  width  b  if  it  be  assumed  that  the 
concrete  resist  one  third  of  the  total  shear  (V)  on  this  width,  and  the  steel  the  remaining  two- 
thirds,  then  for  vertical  stirrups  spaced  a  distance  (S)  apart  longitudinally 


If  the  reinforcing  material  makes  an  angle  of  45°  then  the  area  of  the  steel  becomes  .7  of  this 
value. 

If  the  safe  bonding  strength  of  steel  rods  be  taken  as  80  Ibs.  per  sq.  inch  of  rod  surface,  and  as 
40  Ibs.  per  sq.  inch  of  wire  surface  then  calling  (o)  the  entire  surface  per  inch  of  length  of  rods  in 

y 

a  section  (6)  the  bond  stress  per  unit  of  surface  of  the  bars  =  -  .  ,  -  which  must  be  less  than  80  for 

jdo 

rods  and  less  than  40  for  wire. 


NOTES  ON  POWER  PLANT  DESIGN 


111 


Example : 

A  continuous  slab  8'-4"  span  is  to  carry  a  total  load  of  288  Ibs.  per  sq.  ft.  —  the  slab  to  be 
of  1-2-4  stone  concrete.     Required  depth  »f  slab  and  area  of  reinforcement. 

fc  =  650  Ibs.  sq.  inch. 
.     fs  =  16,000  Ibs.  sq.  inch. 
n=  15 

288  X  100  x  100 
For  strip  12"  wide  M  =—  -  =  20,000 


40,000 


p  = 


650  x  .375  x  .872 
20,000 


188  x  16,000  X  .872 
188 


12  x  12 
=  188 

-  -762% 


=  15.66 


d  =  3.96" 


12 

use  5"  slab. 

Steel  4  x  12  x  .00762  =  .366  sq.  ins.  per  ft.  width 
use  y%"  rods  spaced  3"  on  centres. 

1200 


The  unit  shear  = 


12  x  .87  x  4 


=  29  Ibs. 


The  bond  stress  = 


1200 


.87  x  4  x  (4  x  .375  x  TT) 


74  Ibs. 


Some  types  of  concrete  floors  are  shown  by  illustrations  taken  from  the  Catalogue  of  the 
Clinton  Wire  Cloth  Co.,  Clinton,  Mass.  The  wire  cloth  consists  of  a  wire  mesh  made  up  of  a 
series  of  parallel  longitudinal  wires  spaced  certain  distances  apart  and  held  at  intervals  by  means 
of  transverse  wires  arranged  at  right  angles  to  the  longitudinal  ones  and  electrically  welded  to 
them  at  the  points  of  intersection. 

A  regulation  governing  the  use  of  any  type  of  reinforcement  for  concrete  floors  in  New  York 
City  requires  that  the  system  be  subjected  to  a  load  test.  The  test  is  made  upon  a  sample  floor 
approximating  as  nearly  as  possible  the  conditions  of  actual  construction,  and  the  particular  span, 
slab  and  reinforcement  as  tested  are  approved  by  the  Bureau  of  Buildings  for  one-tenth  of  the 
load  which  the  test  specimen  actually  carries. 

The  following  floor  slabs  have  thus  been  tested  in  New  York  City  and  approved  by  the  Bureau 
of  Buildings  for  the  various  live  loads  as  given : 

The  dias.  of  wire  corresponding  to  W.  &  M.  gages: 


No.  3 
No.  4 

No.  5 
No.  6 


dia. 

.331 

.307 

.283 

.263 


area 
.086 
.074. 
.063 
.054 


No.  7 
No.  8 
No.  9 
No.  10 


dia. 

.244 

.225 

.207 

.192 


area 
.047 
.040 
.034 
.029 


In  this  type  of  reinforcement  the  wire  is  placed  %"  above  the  bottom  of  the  slab  on  all  slabs 
from  3"  to  through  4^"  in  thickness;  1"  above  on  thicknesses  of  5",  6"  and  7"; and  \Y±'  above 
on  slabs  8"  thick. 

Another  reinforcing  material  known  as  "steelcrete"  made  by  the  Eastern  Expanded  Metal 
Co.  of  Boston  is  shown  by  the  illustration  which  appears  on  page  114. 


112 


NOTES  ON  POWER  PLANT  DESIGN 


Approved  Live  Load  200  Pounds  Per  Square  Foot 


fl-Z-5  C/nder 


Approved  Live  Load  250  Pounds  Per  Square  Foot 


-2? -5  Jfonf  Concrete 


Mre 


We/cfed  ttfre 


Approved  Live  Load  150  Pounds  Per  Square  Foot 

_          S  1-2-5  C/nefer  Concrete 


Approved  Live  Load  150  Pounds  Per  Square  Foot 


Approved  Live  Load  300  Pounds  Per  Square  Foot 


Approved  Live  Load  400  Pounds  Per  Square  Foot 


NOTES  ON  POWER  PLANT  DESIGN 


113 


This  cut  also  gives  some  idea  of  the  method  by  which  the  mesh  is  manufactured. 

"Steelcrete"  can  be  obtained  in  lengths  up  to  144"  and  in  lengths  less  than  144"  varying  by 
some  multiple  of  8". 

The  size  of  the  diamond,  weight  of  reinforcement  per  sq.ft., etc.,  are  given  in  the  following 
table  which  has  been  taken  from  the  maker's  catalogue. 


/ 

DECIMAL  STANDARDS 

FOR  "STEELCRETE"  EXPANDED  METAL 

Width  of    Length  of 

Section  in 

Wt.  per 

Number         Size  of  Standard 

Number  of 

Wt.  per 

Diamond     Diamond 

sq.  in.  per 

square  foot 

of  Sheets                 Sheets 

sq.  ft.  in 

bundle  in 

ft.  of  width 

in  Ibs. 

in  a  bundle 

a  bundle 

Ibs. 

Designation  of 

Size  of  Mesh 

Mesh 

3-13-075 

3" 

8" 

.075 

.27 

10 

6'0"x   8'0" 

480 

129  6* 

6'0"  x  12'0" 

720 

194.4 

3-13-10 

3" 

8" 

.10 

.37 

7 

6'9"x   8'0" 

378 

139.9 

6'9"  x  12'0" 

567 

209.8 

3-13-125 

3" 

8" 

.125 

.46 

7 

5'3"x   8'0" 

294 

135.2 

5'3"  x  12'0" 

441 

202.9 

3^-15 

3" 

8" 

.15 

.55 

5 

7'0"x   8'0" 

280 

154.0 

TO"  x  12'0" 

420 

231.0 

3-9-20 

3" 

8" 

.20 

.73 

5 

5'3"x   8'0" 

210 

153.3 

5'3"  x  12'0" 

315 

230.0 

3-9-25 

3" 

8" 

.25 

.92 

5 

4'0"x   8'0" 

160 

147.2 

4'0"  x  12'0" 

240 

220.8 

3-9-30 

3" 

8" 

.30 

1.10 

2 

7'0"x    8'0" 

112 

123.2 

TO"  x  12'0" 

168 

184.8 

3-9-35 

3" 

8" 

.35 

1.28 

2 

6'0"x   8'0" 

96 

122.9 

6'0"  x  12'0" 

144 

184.3 

.3-6-40 

3" 

8" 

.40 

1.46 

2 

7'0"x    8'0" 
TO"  x  12'0" 

112 
168 

163.5 
245.3 

3-6-45 

3" 

8" 

.45 

1.65 

2 

6'3"x    8'0" 

100 

165.0 

6'3"  x  12'0" 

150 

247.5 

3-6-50 

3" 

8" 

.50 

1.83 

2 

5'9"x   8'0" 

92 

168.4 

5'9"  x  12'0" 

138 

252.5 

3-6-55 

3" 

8" 

.55 

2.01 

2 

5'3"x    8'0" 
5'3"  x  12'0" 

84 
126 

168.8 
253.3 

3-6-60 

3" 

8" 

.60 

2.19 

2 

4'9"x   8'0" 
4'9"  x  12'0" 

76 
114 

166.4 
249.7 

3-6-75 

3" 

8" 

.75 

2.74 

2 

3'9"x   8'0" 
3'9"  x  12'0" 

60 
90 

164.4 
246  6 

3-6-100 

3" 

8" 

1.00 

3.66 

2 

2'9"x   8'0" 
2'9"  x  12'0" 

44 
66 

161.0 
241.6 

"STEELCRETE"  SPECIAL  MESHES 

K-13-25 
1^-13-20 
2-13-15 

.95" 
1.36" 

1.82" 

2" 
3" 
4" 

.225 
.181 
.15 

.      .80 
.73 
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5                   4'0"  x  8'0" 
5                   5'0"  x  8'0" 

240 
240 
200 

192.0 
116.8 
100.0 

114 


NOTES  ON  POWER  PLANT  DESIGN 


-For  use  with 

GRAVEL  OR  STONE:  CONCRETE:. 

Maximum  Stress  in  Steel  =  I8,50O  Ibs.per  scj.  inch. 
Maximum  Stress  in  Concrete  =75O)bs.  per  sc^.  inch. 

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/oso 


764 


660 


SOO 


386 


Z38 


SO 


6/0 


3318 


2638  Z//6 


/7Z8 


S434 


/024 


878 


738 


376 


444 


348 


2/7 


/3S 


e/ 


60 


S6S 


/o 


379S  2970 


2383 


/946 


/3£9 


//S4 


989 


033 


649 


JO/ 


393 


Z46 


/9S 


/Zo 


t>9 


42/8 


/Z* 


330? 


26SZ  2/63  /790  /S/2 


//Of 


723 


33? 


439 


347 


4630  364o 


Z92o  2388  /98t  /666 


S4/6 


/Z/4 


/030 


79$ 


6/S 


484 


383 


Z7S 

304- 


Z/8 
Z4Z 


/73 


/04 


7A 


493 


/SO 


fl7 


/8-0" 


404 


238 


/22 


73 


37 


2jr 


7SO 


738 


•S74 


370 


304 


/79 


f/ 


J9 


43 


30 


99/ 


772 


JO/ 


4/3 


344 


290 


246 


/36 


88 


66 


49 


Z4_ 


/26S 


79Z 


6*4 


J3Z 


446 


376 


27S 


206 


69 


/3.2QQ 


J2 


38 


/4f4oo 


/23/ 


004 


666 


472 


4O3 


26/ 


/Zo 


93 


7Z 


J4 


40 


29 


J9 


2Z&S 


/4/7 


$08 


686 


38S 


290 


/84 


/46 


7/ 


/7,8oo 


2823 


Z2/3 


/776 


/2Q7\/0/6 


S64 


74/ 


64/ 


480 


379 


29f 


236 


/89 


93 


74 


37 


70S 


/8.3OO 


3303 


2370 


/7oo 


/4/S 


/o// 


069 


7S/ 


372 


444 


3SO 


270 


/7f 


/42 


00_ 


6  so 


2963 


2370 


/94S 


/6/f 


/36Z. 


99* 


06/ 


40Z 


3Zo 


ZSTi 


/6S 


/03 


80 


4Z3S  334o 


?6So 


2/94 


/ffZ3 


74/ 


2*43  203  / 


/Z3/  /Of 3 


4093\3Z9< 


/37<7 


//94 


J?7- 
643 

7/Q 


433 


36Z 


447 


290_ 
32S 

339 


233 
26/ 

Z8f_ 


/07 


/49 


9/ 


36  S 


2/0 


/04 


t50a/7. 


4-0 


7-o 


7-6 


8-0 


9-o' 


//-o' 


/3-a  /4-d 


/6-o 


/0z6 


800 


638 


ZS6 


2/9 


92 


70 


30 


27 


750 


/2.300 


/32o 


/030 


824 


672 


46S 


393 


333 


ZAfi 


2/6 


74 


/6Z8  /Z73 


/0/9 


832 


6S9 


&SL 


490 


4/9 


Z.7Z 


76 


Jft 


/Z03 


7/4 


244 


/Z2 


7 
8 
9 
/0 


?A- 


3/3/ 


2433  /973 


963 


7/7 


4*27 


33ff 


27* 


2/7 


3660  287o  Z303/a00 


/S7o  /323 


//27 


397 


3/<f 


20 


/67 


/3S 


4/93 


3200  Z643  Z/66  /8o/  /3/£ 


964 


739 


577  457 


296 


239 


/•57 


/O/ 


640 


4725  3703  297?  2438  Zoz?  /7/O 


#33 


324. 


£0 


3Z63\4/ZS  33Z/ 


ZTZ^  2263  /foe"  /627  /39?  /Z//_ 


9Z9 


727 


463 


304_ 


?4± 


£65 


£7fo\434S\36So\Z99/  \249o\Z /OO 


/79o 


8o/ 


£33 


273 


79 


43 


NOTES  ON  POWER  PLANT  DESIGN 


117 


737 


626 


444 


/36 


//O 


6f_ 


730 


/a,  4oo 


22J8  /73#  /406 


?•*£. 


383  303 


382 


293 


/44 


32. 


/2,/QO 


7 


3//8  2443 


/608  /J37  //26 


93? 


824. 


7/*_ 


33Z_ 


2/6_ 


/7S_ 


9o 


7/ 


/3f  7oo 


/760  /433  /266 


722L 


370 


434 


36£~ 


296  242 


/6Z 


/3Z. 


/3,/QO 


~f/73 


406 f  3273  2636  ?2Jff  /#39  /6/4 


/39/ 


/2/0 


932 


734 


S87 


476 


389 


320 


264 


Z/£_ 


/6,3oo 


6330  4??3  4020  3303  Z734  23Z7 


/493  //34 


f*_ 


Z3/_ 


Sf3 


403 


336 


280 


Z34 


74 a  3 3323  4&?ff 


70/ 


377 


474 


394 


334 


233: 


730 


/z 


82/0  6460  3203  4273  33~6<9  3O/S  238O 


ZZ2?  /&?o 


779 


642  333 


•444 


37Z 


3/3 


263 


690 


90/3 


7033  37/3  46?3  39/3 


/307 


#37 


706 


333 


4/2 


346_ 


24/ 


ASS 


/4 


93ZS  -77 ZS  6225  3//S  4Z7i 


36/3 


3o33\  266S  2323  /?<?<?  /42s  //^6 


933 


77/ 


64/ 


•430 


379 


3/9 


/0t3Ji  8J63_  6733_  3333  4623  J£0£  334J_  2jf,9£  Z3/3_ 


4973  42/0 


3600  3/A 


/243_ 


336 


332 


347 


600 


3^2£  444 


373 


4'-o" 


7-o 


/3-0' 


/4-0'  /3- 


/7-o 


/6/3 


6S3 


373 


4/3- 


337 


269 


/6o 


73T 


37 


43 


Z/ 


730 


8*600 


/?3f/a46 


Sff/ 


749 


643 


336 


4Z3 


3Z9 


/04 


S3 


/A/00 


34/3  Z6S/  2/S3 


909 


73? 


473 


376 


2-44 


/99 


/62 


/32 


/07_ 


S6_ 


//,400 


4485\33ZQ  Zg33Z3?3  /933 


/636 


306 


634_ 


^06 


409 


334 


274 


/#7_ 


/34 


/Z^OtL 


3673  4463  33?3  Z<?^ 


/336 


634 


436 


209 


/3.80O 


697o  3~43o 


44/3\3627  JQ3o 


ff/3 


663 


434 


3/9 


/4,8oo 


8363  63S3  33o3 


/343  /2Z& 


937_ 


£03 


663 


337 


467_ 


394_ 


334^ 


283 


7793  62ff£  3/70 


43^o 


J660 


3/32  27/Q  2363 


/33S  /439  //79 


Soz 


67S_ 


£&L 


473_ 


407 


346 


/3 


//478  9o3g 


72 SS  S??J 


/700  /377  //3/ 


94o_ 


666 


366 


4£2_ 


4/3 


/7,90o 


/4 


/2XSS  /0/73  £233  67933665  43oo  4//S  336S  3 '//, 


24ZC 


/923  /36/ 


/234 


/06? 


73f_ 


646_ 


332 


42f_ 


74Q 


/-S 


7333  6/33 


3/<?3  4433  383S  3368^  g£gg 


2o87  /693 


973. 


7*2 


6OO 


3/3 


7/0 


/3//0  //?0o  9600 


7900  6603  S6oo  4ff0o  4/33  J63O  282S\  22S-Q  /82S  /So/ 


/230  /0J0 


389 


73 


643 


336 


118 


NOTES  ON  POWER  PLANT  DESIGN 


•For  use  with 


Maximum  Stress  in  Steel  =  16,000  )bs.  per  scj..  inch. 
Maximupn  Stress  in  Concrete  =30O)bs.  per  so.  inch  . 

Maximum  Bending  Moment^M  *  iz  wlz  . 
where 

w  =  totc»l   load   per  Scj..  ft. 
1st  center*  to  center  span. 


3-S3  -075 


Area  •=  0.  07S  3%.  //?  /><?/"  /?.  0/~  if/a?//?. 


7-0" 


7-6 


8-0' 


9-0- 


/6,  040 


£4 


36 


26 


23S 


60 


43 


Z/3 


2/3 


92 


4/ 


£44 


02 


62 


47 


33- 


/83 


S2? 


/74 


6/ 


43 


/4 


36ff 


277 


37 


42 


/9 


/30 


43^ 


323 


£47 


09 


£7 


23 


372 


£20 


/S3 


79 


39 


/23 


S30 


J9?_ 


67 


33 


/2o 


467 


338 


270 


2/7 


/69 


76 


//O 


682 


393 


/87 


/43 


34 


42 


4-t, 


6-0" 


6-6 


7'o" 


8-0" 


9-o" 


<£•/<?«/ 


/37 


//S 


_^fL 


34 


4/ 


32 


^L. 


/A  /^ 


209 


/30 


_^L 


_2£_ 


_38_ 


J*£- 


^3£L 


Zffo 


232 


//.*• 


3±- 


72 


JiS 


233 


Zf* 


223 


/07 


^Z_ 


£3 


4/ 


23S 


336 


97 


77_ 


40 


.?&- 


220 


420 


320 


/23 


30_ 


70 


62 


37 


/9S 


*&>7 


387 


237 


/08 


/2o 


94 


77 


23- 


S73* 


4S2 


277 


22/ 


/77 


/42 


90 


30 


/60 


670 


403 


2S4 


204 


/64 


36 


/30 


/O 


763 


339 


207 


230 


/49 


74 


4Z 


^S- 


053 


32o 


230 


200 


/67 


/34 


84 


48 


/30 


930 


7/7 


442 


284 


229 


93 


34 


24 


6-0" 


6-6 


7-0' 


7-6 


/o'-o" 


//-o 


/2-o' 


/70 


60 


2/ 


3oo 


/87 


72 


37 


46 


/4.900 


320 


98 


79 


64 


33 


/9 


29o 


374 


264 


224 


/77 


/42 


93 


74 


6/ 


24-. 


26£ 


427 


328 


37 


7/ 


46 


28 


230 


4/0 


3Z/ 


/66 


S36 


9o 


-S7 


37 


ZO 


Z20 


202 


73 


*2L 


_*7_ 


7^3 


079 


_292_ 


237 


/94 


_^2L 


33 


4/6 


336 


274 


224 


/S4 


/32 


66 


40 


/o 


972 


7+S 


469 


379 


30,9 


233 


200 


/7S 


S/3* 


73- 


4S 


^3 


S66 


834 


323 


4Z3 


343 


203 


233 


/3o 


£2- 


/2m 


9/8 


723 


377- 


466 


300 


3/2. 


237 


2/2 


94 


38 


30 


NOTES  ON  POWER  PLANT  DESIGN 


119 


J-9-/3 


of 


3-6 


6-0' 


6-6" 


7-0' 


7-6' 


-O"   /Z-0'  /3-0" 


/82 


#3 


63 


40 


24 


3oo 


/Z3 


63 


40 


24 


'3.300 


74 


60 


3+9 


Z74 


Z/9 


/77 


/43 


40 
33 


36 


/4,800 


23 


/6.000 


399 


J/4 


/37 


93 


64 


43 


27 


Z73~ 


648 


3^4 


3/3 


234 


209 


/43 


ff/ 


33 


33 


20 


Z43 


77V 


473 


38/ 


309 


2S3 


209 


'74 


/43 


43 


9/2 


333 


446 


297 


246 


34 


33 


205 


80S 


3/Z 


4/7 


343 


203 


234 


/97 


93 


64 


40 


'90 


/o 


//78 


9/o 


7/9 


470 


386 


320 


246 


2Z3 


72 


43 


/73 


^03 


443 


323 


298 


/73 


/22 


82 


33 


^3- 


/63 


/Z 


#03 


379 


393- 


32<9 


2.73- 


/94 


9/ 


JT9 


33 


/60 


3-9-20 


4-o" 


4-6 


3-0 


3-6 


6-0' 


•7-6 


8-0 


/0-o'  //-o"  /s-o'  /3-o'  /4-0" 


//ff 


93 


38 


46 


36 


29_ 


300 


9.7oo 


2 


/73 


/37 


-47 


30 


392 


302 


237 


/09 


/33 


S02 


04 


69 


-47 


303 


389 


246 


94 


63 


4S 


29 


628 


3/0 


2^3 


Zo8 


/73 


/44 


60 


27 


867 


674 


43Z 


334 


293 


243 


204, 


/74 


90 


63 


43 


290 


/6.00O 


/046 


ff/3 


£22 


333 


Z97 


230 


2/Z 


/33 


So 


37 


38 


24 


260 


/223 


733 


&// 


348 


293 


248 


/ffo 


67 


240 


/404 


7oz 


338 


286 


80 


33- 


36 


20 


220 


/o 


tSffo 


/ZZ? 


977 


792 


649 


339 


432 


38/ 


323 


233 


S72 


/26 


90 


63 


4/ 


2/0 


/763 


/37o 


833 


723 


603 


303 


427 


J62 


/42 


/03 


72 


48 


/ZOZ 


973 


goo 


£65 


3  £7 


47/ 


Z9Z 


2/4 


/37  ,     Y4 


80 


33 


3/ 


-3-9- 


4-6 


-ff  6-0 


7-6" 


£-0 


9-0" 


/0-0* 


/4-0' 


/£-£ /6-0' 


2/3 


3* 


3/2 


/S7 


79 


4** 


4*^ 
64_ 

93 


3oo 


A400 


33 


77 


33 


36 


7.4*0 


£67 


/49 


7S 


3/ 


313* 


677 


4/6 


336 


Z74 


Z27 


/89 


93 


68 


4<f 


S3 


/2.700 


977 


760 


490 


334 


237 


Z0/ 


/47 


79 


37 


27 


8/4_ 


*£/ 


343 


434 


383 


324 


277_ 


63_ 


3/_ 


/2_ 


/&000 


/33/ 


//94 


933 


773 


32S 


24/ 


/36 


/02 


73 


34 


37 


24 


273 


'092  $£8  732 


3/3 


438 


374 


/37 


80 


64 


43 


29 


230 


382 


494 


423 


3/4 


236 


/79 


/33 


74 


34 


233 


923 


77/ 


63/ 


333 


473_ 


265  20/    /JZ    //4     #4 


60 


40_ 


220 


/£' 


/Z33 


&3Q 


7/7 


6/0 


389  ?73    Z22 


93 


26 


2/0 


3-7-30  <5/&e>/<:r(!-/e 


,Area—  0.300  S0. 


6-6 


7-6 


8-0 


/2-0 


/3-0~  /4-0' 


3" 


Z26 


34 


44 


33 


300 


329 


/27 


84 


69 


37 


3S 


A  3  00 


44S 


346 


273 


/2£ 


/2S 


/oo 


03 


38 


40. 


26 


376 


446 


3S3 


/*£. 


/33 


34 


26 


£ 


7Z/ 


444 


243 


203 


73- 


3jL 


*2L 


//.300 


flat 


642  32/ 


233 


Z/6 


87_ 


4A. 


875 


387 


4/4 


3SZ 


30/ 


1?<L 


97 


22_ 


33 


3* 


/4,440 


//2f 


637 


339_ 


43? 


393 


296 


/72 


/33 


/02 


77 


4/ 


27 


Z/04 


/644  ^-3/3 


888 


744 


629_ 


337 


462 


347 


264 


204 


/37 


70 


33 


22 


200 


/6.000 


/O 


7/0 


6*6 


322 


392 


299 


23/ 


flo 


38 


26 


938 


79^ 


383 


439 


2S9_ 


/36 


9/ 


67 


47__ 


J/ 


243 


876 


4 


644 


37/ 


236 


ZZZ 


/33 


/o/ 


73- 


33 


33 


23S 


120 


NOTES  ON  POWER  PLANT  DESIGN 


NOTES  ON  POWER  PLANT  DESIGN 


121 


122 


NOTES  ON  POWER  PLANT  DESIGN 


Adjoining  sheets  should  be  lapped  8"  on  the  end  and  one  and  one-half  inches  on  the  side.  They 
should  be  wired  together  every  three  feet  on  the  ends  and  every  four  feet  on  the  sides. 

A  reinforcing  fabric  known  as  the  Triangle  Mesh  Concrete  Reinforcement  is  manufactured 
by  the  American- Steel  and  Wire  Co. 

The  tables  which  follow  have  been  copied  from  an  Engineer's  Handbook  published  by  the 
Company. 

^This  triangle  mesh  steel  woven  wire  is  made  with  both  single  and  stranded  longitudinal,  or 
tension  members.  That  with  the  single  wire  longitudinal  is  made  with  one  wire  varying  in  size 
from  a  No.  12  gauge  up  to  and  including  a  K"  dia.,  and  that  with  the  standard  longitudinal  is 
composed  of  two  or  three  wires  varying  from  No.  12  gauge  up  to  and  including  No.  4  wires  stranded 
or  twisted  together. 

^  These  longitudinals  either  stranded  or  solid  are  invariably  spaced  4"  centres,  the  sizes  being 
varied  in  order  to  obtain  the  desird  cross-sectional  area  of  steel  per  foot  of  width.     (See  illustration.) 


Area  of  Steel  Required  per  Fpot  of  Width  for  a  Maximum  Reacting  Moment  of  Slab  of  Given  Thickneat. 

Corresponding  SAFE  BENDING  MOMENT  due  to  applied  load  and  weight  of  looti    ' 

M  —  ^jj-  •=  Jjj  X  Load  pet  K.  ft.  X  (length  el  .pan)*  =•  Bending  Moment  for  allb  supported  oa  two  (UN. 
M  ^  ^  =  Bending  Moment , 

The  Maximum  Allowable  Fiber  Stress  in  the  steel  governs  the  values  of  Relating  Moments  siren  below  ai.d  to  the  left  of  the  heirr  zirzar  line-  the  M  ixlmom  Allowable  Plkr  «M_ 
In  the  concrete  governs  the  values  above  and  to  the  right  of  this  line.  Po,  example  showing  DM  of  tablet  see  page  w 

Maximum  Streaaeas  Steel  =  18.OOO  pound.,  Concrete  =  65O  pound.  Cm 


Total  Thlck- 
neuofSlib 
,nche.  ] 

Center  of  Steel 
to  Bot,  of  Slab 

1*1 
**i 

S-s 

MOMENTS  OF  RESISTANCE  IN  FOOT  POUNDS  PER  FOOT  OF  WIDTH 

CROSS  SECTIONAL  AREA  IN  SQUARE  INCHES  OF  STEEL  REINFORCEMENT  PER  FOOT  OF  WIDTH 

.04 

.06 

.08 

.10 

.12 

.14 

.16 

.18 

.20 

•25 

.30 

.35 

.40 

.45 

.60 

.66 

.60 

.65 

.70 

.75 

.80 

.90 

1.00 

2K 
3 

3^ 

4 

4K 
5 

5K 
6 

6K 
7 

7K 
8 

8* 
9 

9K 
10 

X 
X 

X 

X 
% 

1 
1 
1 

1 
1 

IK 

IK 

IK 

IK 

IK 
IK 

30 
36 
42 

48 

54 
60 
66 
72 

78 
84 
90 
96 

102 
108 
114 
120 

86 
114 
137 
160 

192 

130 
165 
203 
237 

275 
313 
337 

168 
222 
268 
329 

377 

407 
455 
489 

>547 

210 
271 
332 
404 

458 
498 
572 
634 

678 
756 
764 

248 
327 
395 

478 

557 
589 
659 
742 

811 
913 
934 
1023 

1104 

289 
375 
458 
552 

636 
679 
774 
849 

941 
1017 
1103 
1156 

1257 
1346 
1437 

325 
423 

520 
625 

734 
769 
888 
991 

1071 
1172 
1216 
1352 

1409 
1508 
1623 
1728 

341 

353 

377 

578 

611 
858 
1136 

900 
1194 

1519 

1246 

1585 
1764 

1644 
1835 
2232 

1893 
2314 
2756 

2381 
2848 

3334 

3872 

2922 

3431 
3968 
4255 

3525 
4072 
4371 

4963 

5518 
5683 

6125 
6529 

4169 
4464 
5080 

5725 
6077 
655C 
7011 

4259 
4566 
5207 

5860 
6200 
6914 

5309 

5987 
6340 
7055 
7836 

5498 

6201 
6576 
7338 
8114 

6668 

6410 
6788 
7571 
8393 

478 
592 
697 

812 
858 
973 
1095 

1199 
1326 
1383 
1483 

1636 
1670 
1807 
1936 

525 
653 
769 

890 
968 
1086 
1201 

1327 
1478 
1548 
1678 

1786 
1831 
1992 
2144 

804 
954 

1100 
1187 
1337 
1513 

1664 
1831 
1877 
2062 

2232 
2309 
2447 
2660 

1327 
1403 
1612 
1787 

19!)7 
2179 
2257 
2443 

2673 
2703 
2897 
3068 

1637 
1857 
2058 

2286 
2524 
2632 
2820 

3037 
3172 
3343 
3573 

2099 
2359 

2612 
2866 
2951 
3257 

3470 
3560 
3874 
4075 

2625 

2895 
3157 
3320 
3627 

3900 
4021 
4313 
4572 

3216 
3541 
3686 
3995 

4256 
4479 
4749 
5066 

3998 
4360 

4679 
4857 
5182 
5557 

4723 

5100 
5308 
5612 
6044 

7395 

Steel  =  16.OOO  pound..  Concrete  =  TOO  pound. 


jat  -0 

£?•§ 

iia 

Center  of  Steel 
to  Bot,  of  Slab 

l5i 

MOMENTS  OF  RESISTANCE  IN  FOOT  POUNDS  PER  FOOT  OF  WIDTH 

CROSS  SECTIONAL  AREA  IN  SQUARE  INCHES  OF  STEEL  REINFORCEMENT  PER  FOOT  OF  WIDTH 

*s* 

.04 

86 
114 
137 
160 

192 

.06 

.08 

.10 

.12 

.14 

.16 

.18 

.20 

.25 

.30 

35 

.40 

.45 

.50 

.55 

.60 

.65 

.70 

.75 

.80 

.90 

1.00 

2K 
3 

3% 
4 

*K 
5 

5K 
6 

6K 

7 

7K 
8 

8* 
9 

»K 
10 

% 
% 
« 

X 

X 
I 
1 
1 

1 

1 

IK 
IK 

iK 
IK 
IK 
IK 

30 
36 
42 
48 

54 
6O 
66 
72 

78 
84 
90 
96 

102 
108 
114 
120 

130 
165 
203 
237 

275 
313 
337 

168 
222 
268 
329 

377 

407 
455 
489 

547 

210 
271 
332 
404 

458 
498 
572 
634 

678 
756 
764 

248 
327 
395 
478 

557 
589 
659 
742 

811 
913 
934 
1023 

1104 

289 
375 
458 
552 

636 
679 

774 
849 

941 

1017 
1103 
1156 

1257 
1346 
1437 

325 
423 
520 
625 

734 
768 
888 
991 

1071 
1172 
1216 
1352 

1409 
1508 
1623 

1728 

366 
478 
592 
697 

812 
858 
973 
1095 

1199 
1326 
1383 
1483 

1636 
1670 
1807 
1936 

379 

406 
623 

658 
924 

969 
1286 

1532 
1637 
1857 
2058 

2286 
2524 
2632 

2820 

3037 
3172 
3343 
3573 

1342 
1707 

1770 
1976 

2038 

2492 

2565 
3066 

3147 

3698. 

3796 
4386 

4704 

4490 

4802 

4586 
4913 

5607 

5717 

6447 

8828 

5920 

6678 
7081 
7902 
8739 

61M 

6903 
7310 
8154 
9038 

525 
653 
769 

890 
968 
1086 
1201 

1327 
1478 
1548 
1678 

1786 
1831 
1992 
2144 

804 
954 

1100 
1187 
1337 
1513 

1664 
1831 
1877 
2062 

2232 
2309 
2447 
2660 

1137 

1327 
1403 
1612 

1787 

1957 
2179 
2257 
2443 

2673 
2703 
2897 
3068 

1849 
2099 
2359 

2612 
2866 
2951 
3257 

3470 
3560 
3874 
4075 

234(1 
2625 

2895 
3157 
3320 
3627 

3900 
4021 
4313 
4572 

2889 

3216 
3541 
3686 
3995 

4256 
4479 
4749 
5066 

349£ 
3875 

3998 
4360 

4679 
4857 
5182 
5557 

4160 
4358 

4723 

5100 
5308 
5612 
6044 

5084 

5519 
5683 
6125 
6529 

5444 

5866 
6129 
6550 
7011 

6280 
6500 

6973 
7395 

7395 
7968 

Maximum  Streaaeai  SlecT  —  18.OOO  pound*.  Concrete  =  TOO  pound. 


Total  Thick-  1 

new  of  Slab 
Inches 

1| 

•So 

f  I 
of 

l*i 

•2*1 
£•3 

MOMENTS  OF  RESISTANCE  IN  FOOT  POUNDS  PER  FOOT  OF  WIDTH 

CROSS  SECTIONAL  AREA  IN  SQUARE  INCHES  OF  STEEL  REINFORCEMENT  PER  FOOT  OF  WIDTH 

.04 

.06 

1.03 

.10 

.12 

.14 

.16 

.18 

.20 

.25 

.30 

.35 

,40 

.45 

.50 

.55 

.60 

.65 

.70 

.75 

.80 

.90 

1.00 

2K 
3 

3K 
4 

*K 
5 

5K 

6 

«K 

7 

7K 
8 

8K 

9 

»K 
10 

K 
X 
% 
H 

X 
i 
l 
i 

l 
l 
iK 

IK 
IK, 

IK 
iK 

«• 

30 
36 
42 
48 

54 
60 
66 
72 

78 
84 
90 
96 

102 
108 
114 
120 

97 
128 
154 
180 

216 

146 

18S 
228 
267 

308 
352 
379 

189 
250 
301 
370 

424 
456 
512 
550 

616 

237 
305 
373 
454 

516 
.560 
644 
714 

765 
851 
858 

278 
368 
444 
538 

627 
663 
741 
835 

913 
1027 
1050 
1152 

1243 

325 
422 
515 
621 

716 
764 
871 
956 

1059 
1144 
1240 
1300 

1414 
1514 
1618 

353 

367 

378 

406 
623 

658 
924 

969 
1286 

1636 

1821 
2089 
2315 

2571 

2840 
2956 
3173 

3416 
3569 
3761 

4020 

1342 

1707 
1899 
2316 

1770 
1976 
2404 

2871 

2038 
2492 
2968 

3489 
3984 
4143 
4494 

4789 
5038 
5342 
5700 

256C 
9086 

3591 
4170 

4442 

3147 

3896 

4274 
4579 

6210 

•S73S 
5972 
6313 
6810 

3796 

4386 
4704 
5315 

6035 
5373 
6890 
7345 

4490 
•.80S 
WTO 

6166 
6544 

7284 

7888 

4586 
4913 
5607 

6311 

6677 
7446 
8224 

6717 

6447 
Ctftf 
7597 
8440 

5920 

6678 
7081 
7902 
8739 

6104 

6903 
7310 
8154 
9038 

476 
585 
703 

826 
865 
99i 
1115 

1206 
1313 
1366 
1522 

1586 
1697 
1827 
1944 

537 
666 

784 

914 
965 
1095 
1234 

1349 
1491 
1554 
1668 

1840 
1879 
2034 
2180 

57S 

734 

865 

1001 
1090 
1222 

1355 

1493 
1663 
1741 

1887 

2008 
2059 
2240 
2413 

872 

1074 

1239 
1336 
1504 
1702 

1872 
2059 
2110 
2320 

2511 

2598 
2753 
2993 

1223 

1493 
1578 
1814 
2010 

2200 
2452 
2537 

2748 

ax» 

3041 
3259 
3451 

2654 

2938 

3225 
3318 
3664 

3906 
4004 
4358 

4584 

3257 
3651 
3735 
4081 

4386 
4524 
4852 
5144 

490fi 

6264 
5464 
5830 

6252 

124  NOTES  ON  POWER  PLANT  DESIGN 

LONGITUDINALS  SPACED  4-INCH  CENTERS 

CROSS  WIRES  SPACED  4- INCH  CENTERS 

Number  and  Gauge  of  Wires,  Areas  Per  Fcot  Width  and  Weights  Per  100  Square  Feet 

t'  Styles  Marked  *  Usually  Carried  in  Stock. 

Style         No.  of  Wires  Gauge  of  Wire        Gauge  of        Sectional  Area   Sectional  Area  Cross  Sectional   Approximate 

Number        Each  Long  Each  Long        Cross  Wires       Long.  Sq.  In.       Cross  Wires       Area  per  Ft.        Weight  per 

Width  100  Sq.  Ft. 

*4                   1  6                     14                        .087                    .025  .102  43 

51  8                    14                       .062                   .025  .077  34 

61  10                    14                       .043                   .025  .058  27 

*  7                   1  12                    14                       .026                   .025  .041  21 

*23                   1  X"               12tf                   .147                   .038  .170  72 

24  1  4                     12^                   .119                   .038  .142  62 

25  1  5                     12#                    .101                    .038  .124  55 
*26                   1  6                    12#                   .087                   .038  .110  50 
*27                   1  8                    12#                   .062                   .038  .085  41 

28  1  10                     12#                    .043                    .038  .066  34 

29  1  12                     12#                    .026                    .038  .049  28 

31  2  4                     12K                    -238                    .038  .261  106 

32  2  5                    12#                   .202                   .038  .225  92 

33  2  6                     12K                    -174                    .038  .196  82 

34  2  8                     12K                   -124                   .038  .146  63 

35  2  10                    12K                   -086                   .038  .109  50 

36  2  12                    12#                   .052                   .038  .075  37 
*38                  3  4                     12#                   .358                   .038  .380  151 

39  3  5                    12#                   .303                   .038  .325  130 

40  3  6                     12#                    .260                    .038  .283  114 

41  3  8                    l2)/2                   .185                   .038  .208  87 
*42                   3  10                     12#                    .129                    .038  .151  66 

43                  3  12                    123^                   .078                   .038  .101  47 


LENGTH  OF  ROLLS:   150-ft.,  300-ft.  and  600-ft. 

WIDTHS:    18-in.,  22-in.,  26- in.,  30-in.,  34-in.,  38-in.,  42-in.,  46-in.,  50-in.,  54-in.  and  58-in. 


LONGITUDINAL  SPACED  4-INCH  CENTERS 
CROSS  WIRES  SPACED  2-INCH  CENTERS 

Number  and  Gauge  of  Wires,  Areas  Per  Foot  Width  and  Weights  Per  100  Square  Feet 
Styles  Marked  *  Usually  Carried  in  Stock 


Style        No 

.  of  Wires 

Gauge  of  Wire  Gauge  of  Cross 

Sectional  Area 

Sectional  Area 

Cross  Sectional 

Approximate 

Number       Each  Long 

Each  Long 

Wires 

Long.  Sq.  In. 

Cross  Wires 

Area  per  Ft. 

Weight  per 

Sq.  In. 

Width 

100  Sq.  Ft. 

4-A 

1 

6 

14 

.087 

.050 

.102 

53 

5-A 

1 

8 

14 

.062 

.050 

.077 

44 

6-A 

1 

10 

14 

.043 

.050 

.058 

37 

*  7  A 

1 

12 

14 

.026 

.050 

.041 

31 

23-A 

1 

y<" 

12>£ 

.147 

.076 

.170 

86 

24-A 

1 

4 

12^ 

.119 

.076 

.142 

76 

25-A 

1 

5 

12^ 

.101 

.076 

.124 

70 

26-A 

1 

6 

12i/£ 

.087 

.076 

.110 

64 

27-A 

1 

8 

12}4 

.062 

.076 

.085 

55 

*28-A 

1 

10 

12^ 

.043 

.076 

.066 

48 

29-A 

1 

12 

12K 

.026 

.076 

.049 

42 

31-A 

2 

4 

12K 

.238 

.076 

.261 

120 

32-A 

2 

5 

12^ 

.202 

.076 

.225 

107 

33-A 

2 

6 

12>^ 

.174 

.076 

.196 

97 

34-A 

2 

8 

12^2 

.124 

.076 

.146 

78 

35-A 

2 

10 

12>£ 

.086 

.076 

.109 

64 

36-A 

2 

12 

12^ 

.052 

.076 

.075 

52 

38-A 

3 

4 

12^y 

.358 

.076 

.380 

165 

39  A 

3 

5 

12>£ 

.303 

.076 

.325 

145 

40-A 

3 

6 

12K 

.260 

.076 

.283 

129 

41-A 

3 

8 

12^ 

.185 

.076 

.208 

101 

42-A 

3 

10 

12>£ 

.129 

.076 

.151 

81 

43-A 

3 

12 

12>£ 

.078 

"  .076 

.101 

62 

LENGTH 

OF  ROLLS 

:    150-ft.,  300-ft. 

and  600-ft. 

WIDTHS: 

18-in.,  22-in.,  26-  in.,  30-in 

,,  34-in..  38-in 

.,  42-in.,  46-in, 

,  50-in.,  54-in. 

and  58-in. 

NOTES  ON  POWER  PLANT  DESIGN  12<> 

This  table  taken  from  the  Engineer's  Handbook  gotten  out  by  the  American  Steel  and  Wire 
Co.  contains  information  which  may  be  of  use. 


Mixtures 

Required  for  1  cubic  yard  rammed  concrete 

Stone 
1  in.  and  under, 
dust  screened  out 

Stone 
2i  in.  and  under, 
dust  screened  out 

Gravel 

•|  in.  and  under 

1        -2         S 

£           a 

V                  nl                   % 

o         oa          02 

•o       "5 
-£        x 

"5-2            3         -3 
gj2          -„        go 

Sao 
o         a        Z 
o       m       02 

GO                M 

•a        -o 

.to           •*>          >*> 

"S3            3         .3 
£.0        -o       a>o 

1    1:    1 

o>           d          -is 

O        02        m 

TO                « 

.„•    •&   n 

11   .^3   -ft- 

Bed 
8        3        £ 

0       m       O 

1         1.0         2.0 
1         1.0         2.5 
1         1.0         3.0 
1         1.0         3.5 

2.57  0.39  0.78 
2.29  0.35  0.70 
2.06  0.31   0.94 
1.84  0.28  0.98 

2.63  0.40  0.80 
2.34  0.36  0.89 
2.10  0.32  0.96 
1.88  0.29   1.00 

2.30  0.35  0.74 
2.10  0.32  0.80 
1.89  0.29  0.86 
1.71  0.26  0.91 

1          1.5         2.5 
1          1.5         3.0 
1          1.5         3.5 
1          1.5         4.0 
1          1.5         4.5 

2.05  0.47  0.78 
1.85  0.42  0.84 
1.72  0.39  0.91 
1.57  0.36  0.96 
1.43  0.33  0.98 

2.09  0.48  0.80 
1.90  0.43  0.87 
1.74  0.40  0.93 
1.61  0.37  0.98 
1.46  0.33   1.00 

1.83  0.42  0.73 
1.71  0.39  0.78 
1.57  0.36  0.83 
1.46  0.33  0.88 
1.34  0.31  0.91 

1         2.0         3.0 
1         2.0         3.5 
1         2.0         4.0 
1         2.0         4.5 
1         2.0         5.0 

1.70  0.52  0.77 
1.57  0.48  0.83 
1.46  0.44  0.89 
1.36  0.42  0.93 
1.27  0.39  0.97 

1.73   0.53  0.79 
1.61  0.49  0.85 
1.48  0.45  0.90 
1.38  0.42  0.95 
1.29  0.39  0.98 

1.54  0.47  0.73 
1.44  0.44  0.77 
1.34  0.41  0.81 
1.26  0.38  0.86 
1.17  0.36  0.89 

1         2.5         3.5 
1         2.5         4.0 
1         2:5         4.5 
1         2.5         5.0 
1         2.5         5.5 
1         2.5         6.0 

1.45  0.55  0.77 
1.35  0.52  0.82 
1.27  0.48  0.87 
1.19  0.46  0.91 
1.13  0.43  0.94 
1.07  0.41  0.97 

1.48  0.56  0.79 
1.38  0.53  0.84 
1.29  0.49  .0.88 
1.21  0.46  0.92 
1.15  0.44  0.96 
1.07  0.41  0.98 

1.32  0.50  0.70 
1.24  0.47  0.75 
1.16  0.44  0.80 
1.10  0.42  0.83 
1.03  0.39  0.86 
0.98  0.37  0.89 

1         3.0         4.0 
1         3.0         4.5 
1         3.0         5.0 
1         3.0         5.5 
1         3.0         6.0 
1         3.0         6.5 
1         3.0         7.0 

1.26  0.58  0.77 
1.18  0.54  0.81 
1.11   0.51   0.85 
1.06  0.48  0.89 
1.01   0.46  0.92 
0.96  0.44  0.95 
0.91  0.42  0.97 

1.28  0.58  0.78 
1.20  0.55  0.82 
1.14  0.52  0.87 
1.07  0.49  0.90 
1.02  0.47  0.93 
0.98  0.44  0.96 
0.92  0.42  0.98 

1.15  0.52  0.72 
1.09  0.50  0  75 
1.03  0.47  0.78 
0.97  0.44  0.81 
0.92  0.42  0.84 
0.88  0.40  0.87 
0.84  0.38  0.89 

1         3.5         5.0 
1         3.5         5.5 
1         3.5         6.0 
1         3.5         6.5 
1         3.5         7.0 
1         3.5         7.5 
1         3.5         8.0 

1.05  0.56  0.80 
1.00  0.53  0.84 
0.95  0.50  0.87 
0.92  0.49  0.91 
0.87  0.47  0.93 
0.84  0.45  0.96 
0.80  0.42  0.97 

1.07  0.57  0.82 
1.02  0.54  0.85 
0.97  0.51  0.89 
0.93  0.49  0.92 
0.89  0.47  0.95 
0.86  0.45  0.98 
0.82  0.43   1.01 

0.96  0.50  0.76 
0.92  0.48  0.78 
0.88  0.46.0.80 
0.83  0.44  0.82' 
0.80  0.43  0.85 
0.76  0.41  0.87 
0.73  0.39  0.89 

1         4.0         6.0 
1         4.0         6.5 
1         4.0         7.0 
1         4.0         7.5 
1         4.0         8.0 
1         4.0         8.5 
1         4.0         9.0 

0.90  0.55  0.82 
0.87  0.53  0.85 
0.83  0.51   0.89 
0.80  0.49  0.91 
0.77  0.47   0.93 
0.74  0.45  0.95 
0.71   0.4.3   0.97 

0.92  0.56  0.84 
0.88  0.53  0.87 
0.84  0.51  0.90 
0.81  0.50  0.93 
0.78  0.48  0.95 
0.76  0.46  0.98 
0.73   0.44   1.01 

0.83  0.51  0.77 
0.80  0.49  0.79 
0.77  0.47  0.81 
0  73  0.44  0.83 
0.71  0.43  0.86 
0  68  0.42  0.88 
0.65  0.40  0.89 

i  bbl.  cement  &  2  bbl.  sand  will  cover  99  sq.  ft.  of  floor  i  in.  thick. 
j     «          «  j     •<       <«         <«       <«      ^g  "    "     "     "     i  "       " 


126  NOTES  ON  POWER  PLANT  DESIGN 

COSTS 

To  give.an  idea  as  to  the  relative  costs  of  the  different  items  entering  into  the  total  cost  of  a 

Power  House  two  tables  have  been  given.  It  is  seen  from  these  tabulations  that  the  total  cost 
per  K.  W.  exclusive  of  the  land  is  around  $105  for  a  stati9n  of  moderate  size  and  goes  as  low  as  $60 
for  large  stations. 

In  one  station  the  cost  of  piping  may  be  greater  than  that  in  another  of  the  same  size.  This 
may  be  offset,  however,  by  the  lower  cost  of  some  other  item  so  that  the  total  cost  of  the  two  does 
not  differ  much. 

POWER  HOUSE  COST  PER  RATED  K.  W.  INSTALLED    Max.  Min. 

Foundations    .                           .                  ....                  .  $3.50  $1.50 

Sidings,  roadways,  circulating  water  intake  and  discharge  and  buildings  .  15.00  8.00 

Chimneys  and  flues  ...........  3.50  2.50 

Building  Total $2~2750 $12.50 

Boilers,  installed 14.00  8.00 

Superheater 1.50  1.00 

Stokers 10.00  4.00 

Economizers    .         .         .         .         .         .         ,.         .          .         .         .         .  5.00  3.00 

Coal  Conveyor  and  bunkers       .         .         .          .         .         .         .         .         .  6 . 00  2 . 00 

Ash  conveyor          .           .         .         .         .         .         .          .         .         .          .  1 . 50  1 . 00 

Piping  and  pipe  covering  .  .  .  .  .  .  .  .  .  12 . 00  6 . 00 

Feedpumps 1.00  1.00 

Feed  water  heater 2.00  1.00 

Turbine  and  generator 15.00  12.00 

Condenser,  jet  type  .  .  .  .  .  .  .  .  .  .  3.00  2.50 

Exciter 1.50  .75 

Switchboard  .  .  . 4.00  2.50 

Cables  and  conduits  in  power  house    .         .         .         .         .          .         .          .  6 . 00  3 . 00 

Incidentals 2.00  2.00 

Machinery  Total        ...                                              ....  $84.50  $48.75 

Grand  Total  ....  ...  106.50  60.25 

Koester  in  Steam  Electric  Power  Plants  gives  the  following  tabulations  of  costs  for  plants  of 
3000  to  5000  K.W.  capacity. 

COST   OF  TURBINE  PLANTS 

3000  to  5000  K.  W.  —  per  K.  W.  Min.  Max. 

Excavations  and  Foundations    .         .         .         .         .         .         .         .          .  $2 . 00  $2 . 50 

Building .          .  10.00  15.00 

Tunnels.         .                            ...                   .....  1.75  4.00 

Flues  and  Stacks 2.50  3.50 

Boilers  and  Stokers 8.50  12.00 

Superheaters 2.00  2.50 

Economizers 2.00  2.25 

Coal  and  Ash  System 1.50  3.00 

Blowers  and  Ducts .         .                   .  1 . 00  1 . 50 

Pumps  and  Tanks 1 . 00 

Piping  complete 2 . 25  4 . 50 

Turbo-Generators 

Condensers  —  surface        .         .         .         .         .         .         .         .         .         .  5 . 00  8 . 00 

Exciters .75  1.00 

Cranes .25  .50 

Switchboard 

Labor  and  Incidentals        .          .          .          .          .          .          .          .          .  1.00  _2_.  00 

$65.00  $92.00 


NOTES  ON  POWER  PLANT  DESIGN  127 

COST  OF  EXCAVATION  FOR  FOUNDATIONS 

Cost  per  cubic  yard 

Poor  Sand  Pile  onf 

or  wet  clay 

Good0  Good0  Good*         dry  crib  or   ' 

Ledge  Gravel  Sand  Clay  Work  Sand 

1st       5ft.  2.00  0.40  0.30  0.25  0.50  060 

2nf     5ft.  2.75  0.60  0.50  0.35  0.70  0*75 

3-50  0.80  0.70  0.80  1.00  1.5Q 

0  Some  bracing  of  banks  required. 

*  No  bracing  of  banks  required  (large  quantities  excavated), 
t  Average  for  15  feet  depth  without  sheet  piling  $0.90. 

Average  for  15  feet  depth  with  sheet  piling  $1.00. 
Rock  excavation  $2.00  to  $3.00  per  cu.  yd. 
Cement  costs  from  $1.30  to  $1.50  per  bbl. 
Sand  costs  $1.00  per  cu.  yd.  delivered. 
Stone  costs  $1 .00  per  cu.  yd.  at  crusher. 
Concrete  footings  concrete  alone  costs  $7.20  per  cu.  yd. 
Forms  cost  about  12  cents  a  sq.  ft. 

A  rough  estimate  of  the  cost  of  a  footing  including  excavation,  concrete  and  forms  may  be 
made  by  figuring  the  concrete  at  $9.00  per  cubic  yard. 

PILES 

Oak  piles  20-30  ft.  long  12"  butt  6"  top,  17  cents  per  ft.  of  length. 
Oak  piles  40-60  ft.  long,  21  to  25  cents  per  ft.  of  length. 
Spruce  piles  20-30  ft.  long  10"  butt,  15  cents  per  ft.  of  length. 
Cost  of  driving  and  cutting  off,  9  cents  per  ft.  of  length. 
Concrete  piles  in  place  from  $1.25  to  $1.50  per  ft.  of  length. 

BRICKS 

Bricks  per  1000,  $7.50  to  $10.00.  . 

Cost  of  laying  1000  bricks  in  a  wall  10"to  12"  thick  including  mason,  helper  and  staging  is 
$8  to  $8.50.  1000  bricks  laid  make  2  cu.  yds.  masonry  and  cost  $16  to  $18. 

CONCRETE  WALLS  AND  FLOORS 

Concrete  forms  for  floors,  12  cts.  per  sq.  ft. 

Concrete  forms  for  walls  (2  sides)  24  cents  sq.  ft.  wall  area. 

Concrete  wall  6"  thick  including  forms,  costs,  40  cents  per  sq.  ft. 

Concrete,  $7.20  cu.  yard. 

If  there  is  no  abnormal  amount  of  reinforcement  the  cost  of  a  floor  may  be  figured  by  adding 
the  cost  of  the  form  12  cents  per  sq.  ft.  to  the  cost  of  the  concrete  per  sq.  ft.  which  is  $.0222  x  thick- 
ness of  floor  in  inches. 

Where  there  is  an  abnormal  amount  of  reinforcement  the  cost  of  the  steel  should  be  considered. 

STEEL  FRAMEWORK 

The  cost  of  structural  steel  work  varies  with  the  price  of  steel  and  fluctuates  between  $45  and 
$75  per  ton  erected. 

In  general  $60  a  ton  is  a  safe  figure  to  use. 


128  NOTES  ON  POWER  PLANT  DESIGN 

FLUES,   DAMPERS,   ETC. 

Flues  should  be  figured  by  the  cost  per  pound.  A  flue  (y%"  thick)  without  difficult  bends  may 
be  estimated  at  »10  cents  per  pound  erected.  A  flue  may  cost  as  much  as  15  cents  a  pound  where 
there  is  difficulty  in  erecting  it  on  account  of  lack  of  space. 

BOILERS 

A  high  pressure  water  tube  boiler 

400  to  800  H.  P.  per  unit,  $16.50  H.  P.  erected. 
Superheater  for  same,  $1.50  to  $1.00  per  H.  P. 

ECONOMIZERS 

Economizers  $10  to  $12  per  tube  erected  or  about  $4.50  per  Boiler  Horse  Power. 

STOKERS 

Stokers  cost  from  $6  to  $10  per  rated  H.  P.  of  boiler. 

CHIMNEYS 

The  cost  of  Radial  Brick  Chimneys  is  approximately  as  given  below. 
These  costs  being  for  the  structure  above  the  foundations. 

Height  Top  diams.  in  ft. 

Ft.  4  6  8  10  12  14  16 

75  1400 

125 
150 
175 
200 
250  16500  18300  22000  24300 

The  comparative  total  costs  of  a  chimney  150  ft.  tall  8  ft.  diam.  as  given  by  Christie  in  "Chim- 
ney Design  and  Theory"  are: 

Redbrick     ... $8500 

Radial  brick          ......  ...  $6800 

Steel,  self  supporting  full  lined         .......  $8300 

Steel,  self  supporting  half  lined        .......  $7800 

Steel,  self  supporting  unlined  .......  $5820 

Steel  guyed $4000 

COAL  CONVEYOR 

For  a  station  of  15000  K.  W.  capacity  about  $1.15  per  K.W.;  for  5000  K.W.  about  $2.50;  for 
1000  K.  W.  about  $4.00  per  K.  W. 

COAL  BUNKERS 

For  parabolic  form  estimate  steel  if  of  suspended  type,  rods  or  straps  as  $100  per  ton  erected, 
if  of  steel  plate  $75  per  ton  erected.     Add  to  this  the  cost  of  the  concrete  lining. 
If  of  girder  type  figure  steel  as  $65  per  ton  and  add  cost  of  concrete. 


8 

10 

12 

14 

2700 

3700 

4300 

4700 

5100 

6200 

7200 

7800 

8300 

7000 

8000 

9000 

9800 

10500 

11000 

12500 

NOTES  ON  POWER  PLANT  DESIGN 


129 


TURBINES  AND  GENERATORS 

Price  depends  upon  market  conditions  but  generally  around  $13  K.  W. 

Some  quotations  obtained  in  February,  1915,  at  a  time  when  steel  was  low  in  price  were  as 
follows : 


G.  E.  Co. 


TURBINE  AND  GENERATOR 

2000  K.W 

2000  K.  W.  bleeder  type  . 
1000  K.  W. 


2000       . 
Westinghouse        2000  bleeder 

1000       . 

A  Le  Blanc  condenser  for  the 
2000  K.  W.  cost 
1000  K.  W.  cost 


$23,000 
$24,000 
$13,500 

$18,500 
$19,500 
$13,000 

$4250 

S2SOO 


A  cooling  tower  for  3000  K.  W.  26"  vacuum  $7,800  above  foundation. 


COMPARISON  OF  COSTS  OF  DIFFERENT  TYPES  OF  ENGINES* 


Cylinders 


Speed 


Exhaust 


Steam  Consumption 

Lbs.  per  I.  H.  P.  hr. 

non  cond'g         cond'g 


Cost  per  H.  P. 


Simple 


Compound 


Triple  Exp. 


High  speed 
High  speed 
Low  speed 
Low  speed 
High  speed 
High  speed 
Low  speed 
High  speed 
High  speed 
Low  speed 

Non-cond'g 
Cond'g 
Non-cond'g 
Cond'g 
Non-cond'g 
Cond'g 
Cond'g 
Non-cond'g 
Cond'g 
Cond'g 

33 
29 
26 

24 


22 
20 

20 
18 

17 
16 


Engine 
erected 

$17.50 
21.00 
25.00 
27.00 
21.00 
24.50 
30.00 
26.00 
29.00 
37.50 


Bldgs. 

Boilers 
Chimney 

$15.20 
12.00 
14  20 
11.50 
13.10 
11.40 
11.00 
12.50 
10.50 
10.30 


Total 
cost 


$32.70 

33  00 
39.20 
38.50 

34  60 
35.90 
41.00 
38.50 
39.50 
47.80 


*From  Mr.  Chas.  E.  Emery. 


The  following  pages  giving  the  Cost  of  Steam  and  Power  Plant  Equipment  were  taken  from 
an  Article  by  Professor  A.  A.  Potter,  M.  I.  T.  1903,  in  Power,  December  30,  1913. 


130 


NOTES  ON  POWER  PLANT  DESIGN 


TABLE   OF   COSTS   OF  STEAM  AND   GAS   POWER-PLANT   EQUIPMENT 


Name  of  Apparatus 
Air  compressors 


Boilers,  steam 


Condensers 


Economizers 


Type 

Single  cylinder,  belt-driven 
Duplex,  belt-driven 
Compound,  belt-driven 
Single  cylinder,  ^team-driven 
Duplex,  steam-driven 
Compound,  steam-driven 
Vertical,  fire-tube 

Submerged  tubes,  100  Ib.  per  sq.  in.  or  less 
Full  length  tubes:  100  Ib.  per  sq.  in.  or  less 
Horizontal,    fire-tube    cylindrical,    multi- 
tubulai,  100  Ib.  per  sq.  in.  or  less 


Portable  locomotive 

Vertical,  water-tube,  pressures  over  125  Ib. 

per  sq.  in. 
Horizontal,  water-tube,  pressures  over  125 

Ib.  per  sq.  in. 

Barometric  (28-in.  vacuum) 
Jet  condensers 


Surface  condensers 


Number  of  tubes  32  to  10,000,  heating  sur- 
face per  tube  =  12  to  13  sq.  ft. 


Engines,  internal  combustion    Gas  engines 

Gasoline  engines,  hit-and-miss  governor 

Gasoline  engines,  throttling  governor 

Oil  engines  Up  to  400  hp. 

Producer  gas  engines,  American  mfg.  Up  to  300  hp. 

Engines,  steam  Simple, 

Throttling  governor,  slide  valve,  vertical     Up  to  70  hp. 


Capacity 

Up  to  4000  cu.  ft.  per  min. 
Up  to  850  cu.  ft.  per  min. 
Up  to  550  cu.  ft.  per  min. 
Up  to  350  cu.  ft.  per  min. 
Up  to  600  cu.  ft.  per  min. 
Up  to  500  cu.  ft.  per  min. 
Under  20  hp. 
20  to  50  hp. 
Up  to  50  hp. 

Up  to  200  hp. 
Up  to  100  hp. 
100  hp.  to  225  hp. 
Up  to  100  hp. 

100  to  500  hp. 

100  to  600  hp. 

Up  to  30,000  Ib.  of  steam  per  hr. 
Up  to  30,000  Ib.  of  steam  per  hour; 

28-in  vacuum. 
26-in.  vacuum 
Up  to  35,000  Ib.  of  steam  per  hr. ;  28-in. 

vacuum 
Up  to  30.000  Ib.  of  steam  per  hr.;  26-in. 

vacuum 
Capacity  in  Ib.  of  water  per  tube  =  60 

to  70 

Economizer  alone 
Economizer  erected 
Up  to  300  hp. 
Up  to  100  hp. 
Up  to  75  hp. 


Equation  of  Cost  in  Dollars 
52  +  1.95  X  cu.  ft. 
316  +  1.675  X  cu.  ft. 
3.1  X  cu.  ft. 
231  +  2.32  X  cu.  ft. 
460  +  2.55  X  cu.  ft. 
71.25  +  4.025  X  cu.  ft. 
49.2  +  6.66  X  hp. 
116.4  +  3.35  X  hp. 
51.5  +  3.62  X  hp. 

64  +  4.14  X  hp. 
5.8  X  hp.  -  20 
211  +3.35  X  hp. 
121  +  5.68  X  hp. 

912  +  6.28  X  hp. 

149  +  8.24  X  hp. 
1055  +  0.112  X  (Ib.  steam  cond.) 

1176  +  0.1138  X  (Ib.  steam  cond.) 
116  +  0.0591   X  (Ib.  steam  cond.) 

1630  +  0.2038  X  Ob.  steam  cond.) 
413  +  0.1015  X  (Ib.  steam  cond.) 


Throttling  governor,  slide  valve,  horizontal, 


Fans  and  blowers 
Feed-water  heaters 


Generators,  electric 


Motors,  electric 


Upper  limjt  in  cost 

Lower  limit  in  cost 
Simple, 

Flywheel  governor,  piston  or  balanced 

slide  valve,  horizontal 
Automatic  cut-ofi,  single  valve,  vertical 

Flywheel  governor,   Corliss  non-releasing 

valve,  horizontal 
Corliss  governor  and  valves,  horizontal 

Flywheel  governor,  multiple  flat  valves 
Cross  compound, 

Ball  governor,  single-valve,  horizontal 
.  Ball  governor,  single-valve,  vertical 
Flywheel  governor,  multiported  valves, 

horizontal 
Shaft    governor,    Corliss    non-releasing 

valves,  horizontal 
Tandem  compound, 

Flywheel  governor  and  slide  valves,  hori- 
zontal 

Flywheel  governor  and  slide  valves,  ver- 
tical 
Flywheel  governor,  Corliss  non-releasing 

valves,  horizontal 

Flywheel  governor,  multiple  slide  valves 
Sizes  70  to  140  in. 
Open 

Closed 

Direct  current  (voltage  1 10-250),  belted 

Direct-connected 

Alternating-current,  belted 
Direct -connected 

Direct-current,  belted;  smzll  sizes 


Variable  speed 

Alternating  current: 

Single-phase  (110-220  volts) 
Belted ;  polyphase  induction 

Variable  speed 


Up  to  70  hp. 
Up  to  200  hp. 


Up  to  500  hp. 
Up  to  30  hp. 
30  to  150  hp. 

Up  to  600  hp. 
Up  to  400  hp. 
300  to  900  hp. 
Up  to  400  hp. 

Up  to  330  hp. 
Up  to  200  hp. 

Up  to  600  hp. 
Up  to  600  hp. 

Up  to  400  hp. 
Up  to  140  hp. 

Up  to  300  hp. 
Up  to  500  hp. 

Up  to  1500  boiler  hp. 
1500  to  3000  boiler  hp. 
Up  to  3000  boiler  hp. 
Up  to  7  kw.  (1400  to  2300  r.p.m.) 


$8  to  $10  per  tube 
$J2  to  $15  per  tube 
33.6  X  hp.  -  115 
141  +  24.8  X  hp. 
309  +36.1  X  hp. 
63.8  X  hp.  -  316 
400  +  33.5  X  kp. 

63.5  +  17.5  X  hp. 

107  +  13.3  X  hp. 
80  +  5.81   X  hp. 


386  +  6.69  X  hp. 
164  +  9.53  X  hp. 
372.5  +  9.55  X  hp. 

1100  +  8.94  X  hp. 
1040  +  8.45  X  hp. 
730  +  9.1    X  hp. 
685  +  7.69  X  hp. 

735  +  8.0  X  hp. 
750  +  10.4  X  hp. 

1100  +  9.62  X  hp. 
2015  +  9.74  X  hp. 

559  +  8.83  X  hp. 
610  +  12.7  X  hp. 

1295  +  10.79  X  hp. 
1010  +  7.65  X  hp. 
6.25  X  (size  in  inches) 
114.5  +  0.3787  X  hp. 
326  +  0.237  X  hp. 
40  +  0.72  X  hp. 
21.1  +  28.5  X  kw. 


10  kw.  to  300  kw.  (600  to  1400  r.p.m.)  10  X  (kw.)  —  9 


Up  to  300  kw.  (100  to  350  r.p.m.) 
300  to  1000  kw.  (moderate  speed) 
Up  to  300  kv.a.  (600  to  1800  r.p.m.) 
Up  to  300  kv.a.  (200  to  300  r.p.m.) 
250  to  2500  kv.a.  (100  to  250  r.p.m.) 
Up  to  1.5  hp.  (1400  to  2f;00  r.p.m.) 
1.5  to  30  hp.  (1000  to  1800  r.p.m.) 
30  to  100  hp.— Upper  lin.it  (500  to  800 

r.p.m.) 

Lower  limit— (800  to  1000  r.p.m.) 
Up  to  10  hp. — Upper  limit 

Lower  limit 

Up  to  25  hp.  (1200  to  1800  r.p.m.) 
Up  to  130  hp.  (1200  to -1800  r.p.m.) 
Up  to  25  hp. 
35  to  60  hp. 


313.3  +  10.93  X  kw. 
12.08  X  (kw.)  -  383 
81  +  9.723  X  kv.a. 
375  +  7.477  X  kv  a. 
2413  +  4.69  X  kv.a. 
18.53  +  42.37  X  hp. 
53.3  +  12.4  X  hp. 

191.7  +  10.94  X  hp. 
213  +  8.264  X  hp. 

64.1  +  36.7S6  X  hp. 

69.2  +  10.56  X  hp. 

25  +  11.75  X  hp. 
116  +  4.72  X  hp. 
60.7  +  7.15  X  hp. 
157.6  +  3.573  X  hp. 


NOTES  ON  POWER  PLANT  DESIGN 


131 


TABLE  OF  COSTS  OF  STEAM  AND  GAS 


Name  of  Apparatus 
Producers,  gas 

Producer  plants,  gaa 
Pumps 


Purification  plants 

Stokers 


Superheaters 


Transformers 


Turbines,  steam 


Type 

Suction 
Pressure 
Suction 
Boiler  feed 

Single-cvlinder,  piston  pattern 

Duplex,  piston  pattern 
Single-cylinder,  out«ide-packed,  plunger 

pattern 

Duplex,  outside-packed  plunger  pattern 
Centrifugal 

Horizontal,  low-pressure,  single-stage 
Horizontal,  high-pressure,  single-stage 

Horizontal,  high-pressure,  multi-stage 
Vertical,  low-pressure,  single-stage 
Vertical,  high-pressure,  single-stage 
Vertical,  high-pressure,  multi-stage 

Geared  power 
Single  cylinder 
Single-acting,  triplex 
Double-acting,  triplex 

Rotary  force  pumps 

Wet  vacuum  pumps 

Water 
Chain-grate 

Front-feed 
Under-feed 
200  to  750  boiler  hp. 


Air-cooled 
Oil-cooled 


Water-cooled 

Reaction  type: 

Turbine  and  generator 

Impulse  type : 
Turbine  alone 

Turbine  and  generator 


POWER-PLANT  EQUIPMENT 
Capacity 

Up  to  300  hp. 
Up  to  300  hp. 
Up  to  200  hp. 

Up  to  6000  gal.  per  hr. 
6000  to  27,000  gal.  per  hr. 
Up  to  29,000  gal.  per  hr. 

Up  to  24,000  gal.  per  hr. 
Up  to  49,000  gal.  per  hr. 

Up  to  14,000  gal.  per  min. 
Up  to  5000  gal.  per  min. 
5000  to  20,000  gal.  per  min. 
Up  to  2200  gal.  per  min. 
Up  to  20,000  gal.  per  min. 
Up  to  20.000  gal.  per  min. 
Up  to  1100  gal.  per  min. 

Up  to  20,000  gal.  per  br. 
Up  to  83,000  gal.  per  hr. 
Up  to  89,000  gal.  per  hr. 
1200  to  20.000  gal.  per  hr. 
Up  to  13,000  gal.  per  hr. 
13,000  to  50,000  gal.  per  hr. 
1000  to  20.000  gal.  per  hr. 
100  to  300  b  oiler  hp. 
300  to  500  boiler  hp. 
100  to  660  boiler  hp. 
Up  to  600  boiler  hp. 

100  detc.  of  superheat 

200  deg.  of  superheat 

300  deg.  of  superheat 
Sizea  up  to  3000  kv.a 
Sizes  up  to  30  kv.a. 

25  cycles 

60  cycles 
Sizes  30  to  100  kv.a. 

25  cycles 

60  cycles 

Sizea  up  to  1000  kv.a. 
1000  to  3000  kv.a. 

500  to  5000  kw. 
5000  to  10,000  kw. 

Up  to  50  hp. 
50  to  400  hp. 
Up  to  40 kw. 
25  to  350  kw. 
1000  to  10,000  kw. 


•  Continued 

Equation  of  Cost  in  Dollars 

252  +  14.2  X  hp. 
860  +  15.15  X  hp. 
570  +  46.5  X  hp. 

17.8  +  0.2586  X  (gal.  per  hr.) 
106.8  +  0.011045  X  (gal.  per  hr.) 
585  +  0.0115  X  (gal.  per  hr.) 

0.034  X  (gal.  per  hr.) 
0.042125  X(gal.  per  hr.) 

52  +  0.05525  X  (gal.  per  min.) 
61  +  0.0868  X  (gal.  per  min.) 
210  +  0.0567  X  (gal.  per  min.) 
117  +  0.233  X  (gal.  pe:  min.) 
60  +  0.05575  X  (gal.  per  min.) 
50  +  0.0865  X  (gal.  per  min.) 
125.7  +  0.27  X  (gal.  per  min.) 

90  +  0.0316  X  (gal.  per  hr.) 
56  +  0.03867  X  (gal.  per  hr.) 
195  +  0.0148  X  (gal.  per  hr.) 
8  +0.0117   X(gal.  perhr.) 
18  +  0.01435  X  (gal.  per  hr.) 
14  +  0.00863  X  (gal.  per  hr.) 
1000  +  0.2  X  (gal.  per  br.) 
86  +  4.2S  X(hp.)j 
434  +3.1  X(hp.)  f 
312  +3.015  X  (hp.) 
379  +2.785  X  (hp.) 

165  +  2.578  X  (hp.) 
52  +3466  X  (hp.) 
40  +  4.2S  X  (bp.) 
439  +  1.467  X  kv.a. 

52.9  +  8.1  X  kv.a. 
26.2  +  6.25  X  kv.a. 

157  +  4.68  X  kv.a. 
119.5  +  3.57  X  kv.a. 
181  +  1725  X  kv.a. 
805  +  1099  X  kvA. 

3335  +  13.33  X  kw. 
17,500  +  10.5  X  kw. 

171.5  +  10.7  X  hp. 
10.74  X  hp.  —  54 
304.2  +  36.78  X  kw. 
30.4  X  kw.  -  100 
8106  +  11.34  Xkw. 


132  NOTES  ON  POWER  PLANT  DESIGN 

LOAD   FACTOR 

„          Yearly  output  in  K.  W.  hrs. 
The  "Load  Factor"  =  ^^Ti — —  . .     .    ^  w 

8760  x  rated  capacity  in  K.W. 

Yearly  output  in  H.  P.  hrs. 
8760  X  rated  capacity  in  H.P. 

8760  =  24  x  365. 

Yearly  output  K.  W.  hrs. 

The  Station  Load  Factor  =    -p   .    , —     — rr — : — „  w       , : — 

Rated  capacity  in  K.  W.  x  hrs.  plant  ran 

It  is  evident  that  the  higher  the  load  factor  the  cheaper  the  cost  per  K.  W.  hr.  or  per  H.  P. 
hr.  becomes,  inasmuch  as  the  fixed  charges  are  the  same  whether  the  plant  is  running  at  half  load, 
full  load,  full  time,  half  time  or  idle. 

If  a  plant  had  to  be  run  continuously  it  would  be  advisable  to  have  at  least  one  spare  unit 
and  due  to  the  cost  of  this  spare  unit  the  fixed  charge  would  be  greater  than  for  a  plant  which  was 
idle  at  night  and  hence  gave  opportunity  to  make  repairs,  so  that  a  spare  unit  was  not  necessary. 

COST  OF  OPERATION 

The  cost  of  operation  of  a  power  plant  may  be  divided  into: 

A.  Fixed  charges.  1.  Investment. 

2.  Administration. 

B.  Operating  expenses. 

A.  Fixed  Charges. —  These  include  under  (1)  interest  on  the  investment,  generally  taken  as 
5  per  cent;  taxes  1  to  1.5  per  cent;  insurance  .5  per  cent;  depreciation,  a  varying  amount  depend- 
ing upon  the  life  of  the  apparatus  and  maintenance  or  ordinary  repairs,  frequently  taken  as  2.5 
per  cent.     The  maintenance  is  sometimes  charged  against  operating  expense. 

Under  (2)  such  items  as  salaries  of  officers,  clerks,  stenographers,  etc.  not  connected  with  the 
operating  end.  Office  rent  and  office  supplies  are  included. 

B.  Operating  Expenses. —  This  includes  coal,  oil,  water,  supplies  for  boiler  and  turbine  room 
and  labor. 

The  life  of  the  different  items  making  up  the  Equipment  of  a  Power  Plant  may  be  taken  from 
the  following  table: 

LIFE  OF  APPARATUS 

Years 

Belts 

Boilers,  Fire  Tubes 15 

Boilers,  Water  Tubes. 

Breeching  Steel ........ 

Buildings;  Brick,  Concrete,  Steel  Concrete    .....  50 

Coal  Bunkers     . 

Coal  conveyors  —  rectangular,  bucket 

Coal  Conveyor;  Belt  .... 

Cranes      .         . 

Chimneys,  brick         ........ 

Chimneys,  steel,  self-supporting  .... 

Chimneys,  steel  guyed         .         .         . 

Economizers  ......         20 


NOTES  ON  POWER  PLANT  DESIGN  133 

Engines:  Corliss          .         .         .         .         .         .         .         .         .         .25 

Engines :  High  speed .  15 

Feed  pumps,  turbine  centrifugal 15 

Feed  pumps,  plunger 12 

Generators,  D.  C.       ........  20 

Generators,  A.  C.       .         .         .         .         .         .         .         .         .         .  25 

Heaters,  open  type     ..........  20 

Heaters,  closed  type            .........  10 

Motors 20 

Motor  generator  sets 15 

Piping 15 

Steel  Flues         .                   10 

Stokers     ............  7 

Switchboard      ...........  25 

Turbines 15 

Wiring 20 


DEPRECIATION 

If  the  life  of  a  piece  of  apparatus  is  known  to  be  20  years,  that  is  to  say,  at  the  end  of  20  years 
the  apparatus  is  considered  worthless  and  its  value  as  junk  is  enough  to  pay  for  its  removal,  then 
each  year  a  certain  amount  of  money  should  be  put  by  as  a  sinking  fund  so  that  at  the  end  of  the 
20th  year,  this  money  shall  have  accumulated  to  a  sum  sufficient  to  replace  the  apparatus. 

Evidently  if  the  money  put  away  did  not  draw  interest,  5  per  cent  of  the  original  cost  would 
be  added  to  the  sinking  fund  each  year;  if  however,  the  money  drew  4^  per  cent  interest,  com- 
pounded annually,  the  amount  to  be  laid  by  each  year  would  be  3.19  per  cent  of  the  first  cost  of 
the  apparatus  as  is  found  by  reference  to  the  "interest  table"  which  follows: 

IQOfl 

This  table  has  been  calculated  by  means  of  the  formula  X  =    Q  _|_  mn  _  j 

X  =  rate  of  depreciation  expressed  in  per  cent  of  first  cost. 

R  =  rate  of  interest  received,  compounded  annually;  expressed  as  a  decimal. 

n  =  years  of  life  of  apparatus. 

S  =  first  cost  of  apparatus. 

This  formula  may  be  deduced  thus: 

X 
The  amount  of  money  laid  by  each  year  is  -JQQ^ 

There  has  accumulated  then 


at  the  end  of  the  first  year  -j  ~  „  S 

X  X 

at  the  end  of  the  second  year  -TT       (1  +  -^)  +  ~ 


X  X  X 

at  the  end  of  the  third  year  ~8  (1  +  .R)2  +  -^-S  (1  +  R)  +  -^8 

at  the  end  of  the  fourth  year  --S  (1  +  R)3  +  (1  +  R)2  +  j^-S  (!+£)+  -^ 


134  NOTES  ON  POWER  PLANT  DESIGN 

at  the  end  of  the  n*  year  ~r-S  (1  +  R)»'1 -fjLs  (1  +  R)2  +  -^-S  (1  +  R)  + 

1UU  1UU  1UU 

This  summation  should  equal  S. 
Equating  and  solving  for  X. 

100 


(1  +  R)»-1  +  .  .  .  (1  +  R)2  +  (1  +  R)  +1 

X*  -  1 


The  summation  of  a  series  X*~l  .  .  .  X2  +  X  +  1  = 


X  -  1 


,           v      100  (1  +  K)  -  1  IOOR 

hence  X  =  -  ~ — —  = 


(1  +  R)»  -  1         (1  +  R)»  -  1 


RATE  OF  DEPRECIATION 
(Per  Cent  of  First  Cost) 

Rate  of  Interest,  Per  Cent. 


3 

3.5 

4 

4.5 

5 

5.5 

6 

5 

18.83 

18.65 

18.46 

18.28 

18.10 

17.91 

17.73 

6 

15.46 

15.26 

15.08 

14.89 

14.70 

14.52 

14.33 

7 

13.05 

12.85 

12.66 

12.46 

12.28 

12.09 

11.91 

8 

11.24 

11.05 

10.85 

10.66 

10.47 

10.28 

10.10 

9 

9.84 

9.64 

9.45 

9.26 

9.07 

8.88 

8.70 

10 

8.72 

8.52 

8.33 

8.14 

7.95 

7.76 

7.58 

11 

7.80 

7.61 

7.41 

7.22 

7.04 

6.85 

6.68 

12 

7.04 

6.85 

6.65 

6.46 

6.28 

6.10 

5.92 

13 

6.40 

6.20 

6.01 

5.83 

5.64 

5.47 

5.29 

14 

5.85 

5.65 

5.46 

5.28 

5.10 

4.93 

4.75 

15 

5.37 

5.18 

4.99 

4.81 

4.63 

4.46 

4.29 

16 

4.96 

4.77 

4.58 

4.40 

4.22 

4.06 

3.89 

17 

4.59 

4.40 

4.22 

4.04 

3.87 

3.70 

3.54 

18 

4.27 

4.08 

3.90 

3.72 

3.55 

3.39 

3.23 

19 

3.98 

3.79 

3.61 

3.44 

3.27 

3.11 

2.96 

20 

3.72 

3.53 

3.36 

3.19 

3.02 

2.87 

2.71 

25 

2.74 

2.56 

2.40 

2.24 

2.09 

1.95 

1.82 

30 

2.10 

1.93 

1.78 

1.64 

1.50 

1.38 

1.26 

35 

1.65 

1.50 

1.36 

1.23 

1.10 

0.99 

0.89 

40 

1.32 

1.18 

1.05 

0.93 

0.83 

0.73 

0.64 

45 

1.07 

0.94 

0.82 

0.72 

0.62 

0.54 

0.47 

50 

0.88 

0.76 

0.65 

0.56 

0.42 

0.40 

0.34 

7  8 

17.40  17.04 

13.97  13.63 

11.15  11.20 

9.74  9.40 

8.34  8.00 

7.23  6.90 
6.33  6.00 
5.60  5.27 

4.96  4.65 
4.49  4.13 

3.97  3.66 
3.58  3.30 

3.24  2.96 
2.94  2.66 
2.67  2.47 
2.44  2.18 
1.58  1.36 
1.06  0.88 
0.72  0.58 
0.50  0.38 
0.35  0.26 
0.25  0.17 


Assumed  useful  life  of  apparatus  at  left  of  column. 


The  continuous  expense  based  upon  the  original  cost  of  the  plant  is  sometimes  taken  as  14 
per  cent  per  year  divided  as  follows:  interest  5  per  cent;  depreciation  5  per  cent,  repairs  2%  per 
cent,  insurance  }/%  per  cent  and  taxes  1  per  cent. 


NOTES  ON  POWER  PLANT  DESIGN 


135 


OPERATING  COSTS  IN  CENTS  PER  K.  W.  HOUR  FOR  CERTAIN  CENTRAL  STATIONS 

IN  MASSACHUSETTS 


Coal  

.462 

.710 

.618 

.690 

.703 

.565 

.635 

.880 

740 

650 

740 

Wages                      . 

.192 

.262 

.296 

.347 

.360 

.320 

.342 

.538' 

308 

285 

410 

Oil,  Waste,  etc. 

.008 

.009 

.012 

.019 

.027 

.020 

.017 

.032 

.015 

019 

025 

Water                                   .      . 

.024 

.008 

.040 

.055 

.034 

.045 

.032 

.012 

025 

003 

027 

Station  Repairs,  Bldgs. 
Steam  Equipment  Repairs 
Electrical  Equipment  Repairs 
Miscellaneous     

.015 
.042 
.     .056 
.023 

.020 
.020 
.009 
.022 

.052 
.147 
.045 
.000 

.021 
.059 
.046 
.000 

.012 
.055 
.055 
.000 

.023 
.072 
.014 
.021 

.035 
.072 
.014 
.033 

.012 
.037 
.029 
.080 

.017 
.041 
.072 
.024 

.063 
.073 
.019 
040 

.034 
.158 
.011 
000 

Total             , 

.822 

1.060 

1.210 

1.237 

1.246 

1.080 

1.180 

1.620 

1.242 

1  152 

1  412 

Coal  per  ton  $          ... 

.  3.99 

4.75 

3.60 

4.40 

4.79 

3.78 

4.49 

4.68 

4.52 

397 

451 

K.  W.  Hours 

riii+rmf 

SS5 

Q4 

87 

An 

zd. 

47 

d« 

an 

4.n 

37 

a-i 

1,000,000 


BOSTON    ELEVATED    RAILWAY    COMPANY 


Year 

Rated  capacity 38,470 

Yearly  load  factor 

Cost  of  coal  per  K.  W.  hour,  cents        

Labor  plus  labor  on  repairs  per  K.  W.  hour,  cents 

Coal  and  all  supplies  per  K.  W.  hour,  cents     .... 

Total  per  K.  W.  hour,  cents 

Cost  of  coal  per  ton  $ 3.186 

OPERATING  COSTS,  COSTS  IN  CENTS  PER  K.  W.  HOUR 

TYPICAL  BRITISH  ELECTRIC  LIGHT  AND  POWER  PLANTS  — 1902 

(From  Engineering  Record  —  March,  1904) 


1906 

1908 

1910 

1912 

38,470 

50,425 

51,163 

61,350 

43 

37 

41.5 

36.4 

.47 

.56 

.48 

.41 

.17 

.21 

.17 

.17 

.60 

.86 

.58 

.52 

.77 

1.07 

.75 

.69 

3.186 

3.568 

3.283 

3.202 

K.  W. 

installed 


6380 

8740 

1340 

10477 

3700 

850 

21190 

1600 

5642 

1920 

610 

990 


Yearly 
load 
factor 
per  cent 
20.93 
12.31 
17.84 
14.75 
18.87 
.28.44 
25.11 
15.82 
12.97 
13.31 
14.54 
19.79 


Coal 


.52 
.56 
.52 
.68 
.70 
.82 
.74 
.74 
.92 
.72 
.92 
1.10 


Oil,  waste 

and 
Supplies 

.10 
.06 
.06 
.08 
.12 
.06 
.12 
.08 
.20 
.12 
.20 
.08 


Wages 


.16 
.34 
.34 
.18 
.30 
.30 
.30 
.40 
.32 
.36 
.36 
.42 


Repairs 


.26 
.28 
.38 
.36 
.20 
.22 
.26 
.30 
.18 
.46 
.22 
.18 


Total 


1.04 
1.24 
1.30 
1.30 
1.32 
1.40 
1.42 
1.52 
1.62 
1.66 
1.70 
1.78 


TOTAL  COST  IN  DOLLARS  OF  A  H.  P.  FOR  A  YEAll  ON  10  HOUR  BASIS 


Size  of  Plant                                                        Maximum  Cost 
H.  P.                                                                  per  H.  P. 
2000                        24          . 

Minimum  Cost 
per  H.  P. 
21 

1500      ...                                             26 
1200      ...                                             30 
1000      .                  .                                             33 
800      ...                                             38 
600      ...                                             46 
500                                 ....          50          .. 

21 
22 
24 
26 
28 
31 

400      .                  57          .. 
300                                         ...          65          . 

33 
38 

200                                          ...          77          . 

45 

100      .                          ....          96          .         r 
50                                                                    HO 

60 
80 

130          .         . 

110 

136 


NOTES  ON  POWER  PLANT  DESIGN 


DISTRIBUTION  OF  OPERATING  COSTS 

The  operating  cost  per  K.  W.  hour  varies  from  less  than  one  cent  in  the  large  plants  to  three 
and  one-half  cents  in  the  small  plants.  Plants  of  from  2000  to  5000  K.  W.  capacity  would  operate 
.between  one  and  one-half  and  one  and  one-tenth  cents. 


The  cost  is  distributed  about  as  follows: 


Coal      . 

Wages  .... 

Oil  and  waste,  etc. 

Water   .... 

Station  Repairs,  Bldgs.    . 

Steam  Equipment  Repairs 

Electrical  Equipment  Repairs 


Per  Cent 
56.0 
28.0 

2.0 

2.0 

1.6 

6.3 

4.1 

100.0 


A  certain  station  of  10,000  K.  W.  rated  capacity  cost  $100  per  K.  W.  This  cost  was  divided 
as  follows:  Buildings  $20,  Machinery  $80.  Charging  14  per  cent  on  machinery  and  7.5  per  cent 
on  buildings  gives  for  fixed  charges, 

.075  x  200,000  =    15,000 
.14    x  800,000=  112,000 

127,000 

Suppose  the  yearly  load  factor  is  18  per  cent  and  that  the  total  operating  cost  per  K.  W.  hour, 
is  1.121  cents. 

The  total  output  in  K.  W.  hours  for  the  year  is 

8760  x  10,000  x  .18  =  15,768,000 
$127000  H-  15,768,000 

gives  the  overhead  charge  per  K.  W.  hour  to  be  added  to  the  operating  cost.     This  figures  as  .804 
cents. 

.804  +  1.12  =  1.925  cents. 

It  is  evident  that  the  higher  the  load  factor  the  less  the  overhead  to  be  added  per  K.  W.  to 
operating  cost. 


COST  OF  STEAM  POWER 

Size  of  plant  in  H.  P 

Cost  of  plant  per  H.  P.      .          . 

Fixed  charge,  14  per  cent  ...... 

Coal  per  H.  P.  hour,  in  pounds 

Cost  of  coal  at  $5  per  ton  .          .          .         .         .         . 

Attendance,  3080  hours      ....... 

Oil,  waste  and  supplies 

Cost  1  H.  P.  per  annum,  10-hour  basis         .... 
Cost  of  1  H.  P.  per  hour 


(Small  Units) 
6 

10 

20 

$250.00 

$220.00 

$200.00 

$35.00 

$30.80 

$28.00 

20 

15 

12 

$154.00 
75.00 
15.00 

$103.00 
50.00 
10.00 

$82.50 
30.00 
6.00 

$279.00 
$0.0906 

$194.80 
$0.0832 

$146.50 
$0.0475 

NOTES  ON  POWER  PLANT  DESIGN 


137 


COST  OF  GASOLENE  POWER  —  Small  Units 


Size  of  plant  in  H.  P. 
Price  of  engine  in  place  . 
Gasolene  per  B.  H.  P.  per  hour 
Cost  per  gallon 

Cost  per  3,080  hours       . 

Attendance  at  SI  per  day 
Interest,  5  per  cent 
Depreciation,  5  per  cent 
Repairs,  10  per  cent 
Supplies,  20  per  cent 
Insurance,  2  per  cent 
Taxes,  1  per  cent 

Power  Cost 


Engineering  News,  Aug.  15,  1907. 

2  6 

$150.00  $325.00 

•         •          •  1A  gal.  M  gal. 

$0.20 


$451.53 


$825.03 


$924.00 


10 

$500.00 

Kgal. 

$0.19 


$975.13 


$1371.75          $1498.13 


20 
$750.00 


$0.18 


$1386.00 


308.00 

308.00 

308.00 

308.00 

7.50 

16.25 

25.00 

37.50 

7.50 

16.25 

25.00 

37.50 

15.00 

32.50 

50.00 

75.00 

30.00 

65.00 

100.00 

150.00 

3.00 

6.50 

10.00 

15.00 

1.50 

3.25 

5.00 

7.50 

$2016.50 


To  these  figures  should  be  added  charges  on  space  occupied  as  follows : 
Value  of  space  occupied $100.00 

Interest,  5  per  cent  ...... 

Repairs,  2  per  cent  ...... 

Insurance,  1  per  cent  ...... 

Taxes,  1  per  cent  .          .          .         . 

Total  annual  charge  for  space  .... 

Total  cost  per  annum     ...... 

Cost  of  1  H.  P.  per  annum,  10  hour  basis 
Cost  of  1  H.  P.  per  hour          ... 


$150.00 


$200.00 


$300.00 


$5.00 
2.00 
1.00 
1.00 

$7.50 
3.00 
1.50 
1.50 

$10.00 
4.00 
2.00 
2.00 

$15.00 
6.00 
3.00 
3.00 

$9.00 

$13.50 

$18.00 

$27.00 

$833.03 
416.51 
$0.1352 

$1385.25 
239.87 
$0.0780 

$1516.13 
151.61 
$0.0492 

$2043.30 
102.17 
$0.0331 

COST   OF  GAS   POWER  —  Small  Units 


.50  per  1000  cubic  feet  of  gas  less  20  per  cent,  if  paid  in  10  days  =  $1.20  net,  gas  760  B.  T.  U. 
Size  of  plant  in  H.  P. 

Engine  cost  in  place 


Gas  per  H.  P.  hour  in  cu.  ft. 


Value  of  gas  consumed,  3080  hours 

Attendance,  $1  per  day 

Interest,  5  per  cent         .          .          .          . 

Depreciation,  5  per  cent 

Repairs,  10  per  cent  *     . 

Supplies,  20  per  cent      .          . 

Insurance,  2  per  cent      . 

Taxes,  1  per  cent  . 

Power  cost  * 

Annual  charge  for  space 

Total  cost  per  annum     . 

Cost  of  1  H.  P.  per  annum,  10  hour  basis 

Cost  of  1  H.P.  per  hour 


2 

6 

10 

20 

$200.00 

$375.00 

$550.00 

$1050.00 

30 

25 

22 

20 

$221.76 
308.00 
10.00 
10.00 
30.00 
40.00 
4.00 
2.00 

$554.40 
308.00 
18.75 
18.75 
37.50 
75.00 
7.50 
3.75 

$843.12 
308.00 
27.50 
27.50 
55.00 
110.00 
11.00 
5.50 

$1478.00 
308.00 
52.50 
52.50 
105.00 
210.00 
21.00 
10.50 

$615.76 
9.00 

$1023.65 
13.50 

$1387.62 
18.00 

$2237.50 
27.00 

$624.76 
312.38 
$0.1014 

$1037.15 
172.86 
$0.0561 

$1405.62 
110.56 
$0.0456 

$2264.50 
143.22 
$0.0367 

138  K          NOTES  ON  POWER  PLANT  DESIGN 

GUARANTEES 

It  is  customary  to  ask  that  contractors,  when  submitting  a  bid  for  prime  movers  or  for  power- 
driven  machinery,  give  a  guarantee  as  to  the  performance  or  efficiency  of  the  equipment  they  pro- 
pose to  furnish.  f- 

This  guarantee  may  in  the  case  of  a  steam  engine  be  based  on  pounds  of  steam  per  I.  H.  P. 
or  per  K.  W.  hour  at  rated  load  which  should  be  specified,  as  should  also  the  pressure  and  con- 
dition of  the  steam  at  the  throttle  and  the  temperature  of  the  cold  condensing  water. 

The  steam  consumption  at  half  load  and  at  twenty-five  per  cent  overload  may  also  be  given 
and  included  in  the  guarantee. 

The  performance  of  large  pumping  engines  is  stated  in  figures  representing  the  "duty"  or 
foot  pounds  of  water  work  done  per  1,000,000  B.  T.  U.  or  per  1000  Ibs.  of  steam  of  quality  and 
pressure  specified. 

The  performance  of  centrifugal  pumping  units  when  motor  driven  is  often  given  in  overall 
mechanical  efficiency  of  pump  and  motor  when  working  at  stated  conditions  as  to  head  and  capacity. 

In  contracts  containing  a  guarantee  as  to  performance,  provision  is  made  for  deducting  from 
the  first  cost  of  the  apparatus  a  fixed  amount  for  each  fraction  of  a  pound  the  engine  or  turbine 
exceeds  the  consumption  mentioned  in  the  guarantee;  similarly  in  the  case  of  a  high  duty  pumping 
engine  a  deduction  is  made  for  each  million  duty  under  that  guaranteed. 

It  is  not  necessary  that  there  be  a  "bonus"  for  a  performance  better  than  that  guaranteed. 

The  deduction  made  from  the  original  price  in  case  of  a  failure  to  meet  the  guarantee  is  in  no 
way  to  be  in  the  nature  of  a  penalty.  It  must  be  that  amount  which  the  purchaser  would  lose  in 
money  and  accrued  interest  during  the  life  of  the  apparatus  through  the  less  efficient  performance 
than  that  guaranteed. 

For  example,  a  certain  contractor  guaranteed  a  steam  consumption  per  I.  H.  P.  hour  on  an 
engine  and  condenser  and  failed  to  meet  his  guarantee. 

The  contract  read  that  should  the  steam  consumption  per  I.  H.  P.  at  full  load,  namely  2000 
I.  H.  P.,  exceed  13.7  Ibs.  per  I.  H.  P.  hour  a  deduction  is  to  be  made  from  the  original  contract 
price  at  the  rate  of  $4400  per  1/10  Ib.  that  the  actual  performance  exceeds  the  guaranteed  steam 
consumption,  provided  the  steam  consumption  does  not  exceed  that  guaranteed  by  as  much  as 
3/10  of  a  pound.  Should  the  steam  consumption  at  full  load  exceed  that  guaranteed  by  3/10  of 
a  pound  or  more,  the  purchaser  could  at  his  option  reject  the  engine. 

The  figure  $4400  was  arrived  at  in  this  way  : 

The  life  of  the  engine  may  be  taken  as  18  years  and  it  may  be  assumed  to  run  3000  hours  per 
year  with  full  load  in  this  case.  The  extra  steam  per  hour  per  1/10  Ib.  in  excess  of  guarantee  is 
per  year  .1  x  2000  x  3000  =  600,000  Ibs.  for  engine  alone.  Adding  10%  of  this  as  the  extra  steam 
used  by  the  auxiliaries  makes  660,000  Ibs.  Assuming  9.5  Ibs.  actual  evaporation  per  Ib.  of  coal 
makes  the  extra  coal  per  year  69,474  Ibs.  or  34.74  tons.  With  coal  at  $4.50  per  ton  this  figures 
$156.33. 

If  money  draws  5  per  cent  interest,  the  loss  at  the  end  of  18  years  may  be  figured  as  follows  : 

End  of  first  year,  156.33 

End  of  second  year,  1.05  x  156.33  +  156.33 

End  of  third  year,  1.05  x  156.33  +  1.05  x  156.33  +  156.33 

End  of  fourth  year,  1,06*X  156.33  +  1.05*X  156.33  +  1.05  x  156.33  +  156.33 

End  of  18th  year,  1.0517  X  156.33  +  1.0516  x  156.33  +  ____  1.05  x  156.33  +  156.33 

=  $4402.25 

.  If  R  is  taken  as  the  rate  of  interest;  n  =  number  of  years  and  the  loss  for  the  first  year  is  $1. 
This  may  be  written: 


which  may  be  put  into  this  form  Q  ,   ™n  _ 

R 


NOTES  ON  POWER  PLANT  DESIGN  139 

One  dollar  lost  each  year  plus  the  interest  which  would  have  accrued  would  at  the  end  of  n 

(1  +  R}n  —  1 
years  amount  to ~—  —  which  is  the  "annuity  value  of  one  dollar."  • 

In  the  case  just  considered  this  gives 

(1  +  .05)18  -  1 


.05 


=  28.16  28.16  x  156.33  =  $4402.25 


A  guarantee  on  the  duty  of  a  12,000,000  gallon  pump  read  as  follows:  "With  steam  at  the 
throttle  of  150  Ibs.  gage  pressure  and  containing  not  over  1^  per  cent  moisture,  the  pump  is  guaran- 
teed when  pumping  12,000,000  U.  S.  gallons  in  24  hours  against  a  total  head  of  200  feet  to  give 
a  duty  of  140,000,000  per  1000  Ibs.  of  steam." 

"Should  the  pump  fail  to  make  the  duty  guaranteed  an  amount  representing  the  monetary 
loss  suffered  by  the  city  in  a  period  of  20  years,  taken  as  the  life  of  the  pump,  is  to  be  deducted 
from  the  original  contract  price  of  the  pump." 

"The  amount  to  be  deducted  per  1,000,000  loss  of  duty  as  calculated  and  mutually  agreed 
upon  by  engineers  representing  the  city  and  the  contractor  is  $2116.41." 

"The  extra  cost  of  coal  per  year  per  million  loss  of  duty,  figured  on  coal  at  $4.60  a  ton  with 
an  evaporation  of  10  Ibs.  of  water  per  pound  of  coal  and  on  the  basis  that  the^ump  runs  only 
90  per  cent  of  the  year  and  that  it  runs  at  5/6  of  its  rated  capacity  is  $63.94.' 

The  annuity  value  of  $1  for  20  years  at  5  per  cent  is  $33'.  1. 

63.94  x  33.1  =  $2116.41. 
The  calculations  are  outlined  below: 

365.  x  .9  =  328.5  days 
12,000,000  x  5/6  =  10,000,000  gals,  per  24  hours. 

328.5  x  10,000,000  x  8.33  x  200  =  ft.  Ibs.  per  year. 

Ft.  Ibs.  per  year  _  steam  used  per  year  _  „„  „£  ™\ 
140,000,000  1000 

Ft.  Ibs.  per  year  _  steam  used  per  year 
139,000,000  ~  1000 

Steam  per  year  Coal  per  year,  Ibs.  Coal  per  year,  tons 

B  39,370,000  3,937,000  1968.5 

A  39,092,000  3,909,200  1954.6 


13.9 


13.9  x  4.60  =  $63.94 
63.94  x  33.1  =  $2116.41 


140  NOTES  ON  POWER  PLANT  DESIGN 


PIPING 

Steel  pipe,  is  cheaper  than  wrought  iron  pipe  and  is  generally  furnished  when  an  order  is  given 
for  pipe  unless  wrought  iron  pipe  is  specifically  called  for. 

There  are  two  weights  of  pipe  in  addition  to  the  Extra  Strong  and  Double  Extra  Strong  one 
known  as  "Merchant,"  and  the  other  known  as  "Card"  or  "Full  Weight"  pipe. 

The  term  "Standard"  or  "Merchant,"  is  used  to  describe  a  pipe  not  "Card"  or  "Full  Weight." 

For  many  purposes  this  lighter  weight  is  just  as  good  as  the  "Full  Weight." 

The  term  "Card"  or  "Full  Weight"  refers  to  a  pipe  of  weights  as  given  in  the  table  which 
follows. 

Pipe  in  sizes  up  to  and  including  12"  refers  to  inside  dia.  Above  12"  the  pipe  is  rated  by  the 
outside  dia. 

Pipe  comes  in  lengths  of  from  18  ft.  to  21  ft.  and  in  figuring  the  cost  of  a  system  of  piping 
there  is  some  waste  pipe  which  must  be  taken  account  of. 

Pages  141  to  154  are  taken  from  the  catalogue  of  the  Walworth  Mfg.  Co.  The  discounts 
vary  from  time  to  time  but  may  be  assumed  as  being  approximately  correct. 

The  coefficient  of  expansion  of  steel  piping  is  .0000065  or  in  other  words,  a  pipe  expands  .0000065 
its  length  per  degree  F. 

The  expansion  on  high  pressure  work  is  taken  care  of  by  expansion  bends  similar  to  those 
shown  on  the  plot  (page  155). 

The  amount  of  motion  such  bends  will  provide  for  has  been  determined  experimentally  by 
the  Crane  Company.  The  results  of  this  work  were  published  in  the  Valve  World  of  October, 
1915.  This  plot  is  reproduced  from  that  paper. 

If  the  total  expansion  to  be  taken  up  by  a  double  offset  or  U  bend  is  5"  in  general,  the  bend 
or  offset  would  be  sprung  apart  one-half  the  expansion,  or  in  this  case  2j/£"  when  the  pipe  was 
erected.  By  this  means  the  expansion  first  relieves  the  stress,  then  puts  into  the  pipe  a  stress  of 
the  opposite  kind  but  of  equal  amount. 

Much  of  the  high  pressure  piping  put  up  to-day  has  outlets,  taking  the  place  of  cast  tees, 
welded  to  the  pipe.  This  saves  joints  and  thereby  reduces  the  trouble  from  leaky  gaskets. 

The  labor  cost  of  the  erection  of  piping  depends  upon  the  design  of  the  system;  in  general 
however,  for  the  ordinary  power  house  the  cost  varies  from  15  per  cent  to  25  per  cent  of  the  first 
cost  of  the  fabricated  material;  15  per  cent  would  be  considered  a  low  cost;  20  per  cent  about  an 
average  value. 

Card  or  Full  Weight  pipe  is  generally  used  for  pressures  carried  in  power  plants. 

The  discount  on  card  or  Full  Weight  is  68  per  cent.  The  discount  on  Extra  Strong  62  per 
cent;  on  Double  Extra  Strong  45  per  cent. 


NOTES  ON  POWER  PLANT  DESIGN 


141 


PRICE  LIST  OF 

WROUGHT  IRON  AND  STEEL  PIPE. 


Nominal 
Inside 
Diameter. 

STANDARD. 

EXTRA  STRONG.         I  DOUBLE  EXTRA  STRONG 

Price 
Per  Foot. 

Nominal 
Weight 
Per  Foot. 

Price 
Per  Foot. 

Nominal 
Weight 
Per  Foot. 

Price 
Per  Foot. 

Nominal 
Weigh! 

Per  Foot. 

Vs 

.05l/2 

0.24 

.11 

0.29 

J/4 

.05% 

0.42 

11 

0.54 

% 

.05% 

0.56 

11 

0.74 

.25 

96 

>/2 

.08  V2 

0.85 

.12 

1.09 

.25 

1.70 

% 

.HVz 

1.12 

15 

1.39 

.30 

2.44 

1 

.16V2 

1.67 

.22 

2.17 

.37 

3.65 

Hi 

.22% 

2.24 

.30 

3.00 

.52 

5.20 

l>/2 

.27 

2.68 

.36 

3.63 

65 

6.40 

2 

.36 

3.61 

.50 

5.02 

95 

9.02 

2V2 

.57'/2 

5.74 

.81 

7.67 

1.37 

13.68 

3 

.75% 

7.54 

1.05 

10.25 

1.92 

18.56 

3!'s 

.95 

9.00 

1.33 

12.47 

2.45 

22.75 

4 

1.08 

10.66 

1.50 

14.97 

2.85 

27.48 

«4 

1.30 

12.49 

1.95 

18.22 

3.30 

32.53 

5 

1.45 

14.50 

2.16 

20.54 

'      3.80 

38.12 

6 

1.88 

18.76 

2.90 

28.58 

5.30 

53.11 

7 

2.35 

23.27 

3.80 

37.67 

6.25 

62.38 

8 

2.50 

25.00 

8 

2.82 

28.18 

4.30 

43.00 

7.20 

71.62 

9 

3.40 

33.70 

5.00 

48.73 

10 

3.50 

35.00 

10 

4.00 

40.00 

5.50 

54.74 

12 

4.50 

45.00 

6.50 

65.42 



12 

4.90 

49.00 

On  orders  for  8-inch,  10-inch.  12-inch  pipe  we  will  ship  8-inch,  25  Ib.,  10-inch,  35  lb.,  12-inch,  45  Ib., 
unless  otherwise  specified.  Customers  should,  however,  always  indicate  which  weight  is  wanted. 

When  Standard  Pipe  is  ordered,  black  pipe,  random  lengths,  with  threads  and  couplings,  will  be  shipped, 
unless  otherwise  specified. 

For  pipe  smoothed  on  the  inside,  known  as  plugged  and  reamed,  an  extra  charge  will  be  made  above 
regular  pipe. 

Extra  Strong  and  Double  Extra  Strong  Pipe  will  be  shipped  in  random  lengths  and  plain  ends,  unless 
otherwise  ordered.  For  this  pipe,  fitted  with  threads  and  couplings,  an  extra  charge  will  be  made  above 
regular.  For  cut  lengths  of  any  pipe,  an  extra  charge  will  be  made  above  random  lengths.  For  galvanized 
or  asphalted  pipe,  an  extra  charge  will  be  made  above  black. 

For  Price  List  for  Cutting  and  Threading,  see  page  79. 


GALVANIZED  FLANGED  FITTINGS. 

Faced  and  Drilled. 


SPIRAL  RIVETED  GALVANIZED  PRESSURE  PIPE. 

Lengths  up  to  20  Feet. 


Size. 
Inches. 
3 

90"  Elbows. 
Galvanized 
2.80 

45°  Elbows. 
Galvanized. 
2.35 

Tees. 
Galvanized. 
4.40 

Reducing  Tees 
Galvanized. 
4.75 

Crosses. 
Galvanized. 

5.85 

Y-Branches. 
Galvanized. 

Size. 
Inches. 

u.  s. 

Standard 
Gauge. 

Per  Foot. 
Galvanized. 
No  Flanges. 

'  Flanges 
Attached. 
Each. 

"  Diameter 
Flanges. 
Inches. 

Bolt 
Circle. 
Inches. 

No 

of 
Bolts. 

Size 
Bolts. 
Inches. 

4 
5 

4.00 
5.50 

3.70 
4.90 

6.40 
8.00 

7.00 
8.80 

9.70 
12.00 

9.90 

12.60 
16  50 

4 
5 

18 
18 

.680 
.826 

2.30 
2.70 

7 
8 

5>*i« 

6'V. 

8 

S 

%6 
7/16 

7 
8 
9 
10 
12 
14 

8.00 
12v^0 

17.00 
19.20 
26.60 
41  70 

6.00 
9.50 
14.00 
15.00 
22.00 
2400 

11.20 
18.00 
22.50 
26.00 
41.00. 
61  00 

12.00 
19.00 
24.00 
28.00 
44.00 
66.00 

19.00 
31.00 
40.00 
50.00 
72.00 
86.00 

18.70 
2T.OO 
37.50 
50.00 
71.00 
100.00 

6 
7 
8 
9 
10 
12 

16 
16 
16 
16 
16 
16 

1.0) 
1.216 
1.395 
1.561 
1.731 
2.067 

:;.15 

3.40 

4.05 

i.W 

5.45 
5.85 

9 
10 
11 

0 

14 
16 

7% 
9 
10 

11V4 
12'/4 

14  ¥t 

8 
8 
8 
8 
8 
12 

% 

% 
% 

Vi 

S 

% 

15 
16 
18 
20 
22 
24 

53.00 

76.00 
91.00 
120.00 
142.00 
17800 

30.00 

49.00 
70.00 
84.00 
100.00 
12200 

76.00 
113.50 

148.00 
157.00 

206.00 
25300 

82.00 
122.00 
159.00 

168.00 
222.00 
27200 

108.00 
138.00 
174.00 
197.00 
260.00 
325.00 

116.00 

168.00 

191.00 

208.00 
26(1.00 
336.00 

15 
16 
18 
20 
22 

14 
14 
14 
14 

12 

2.91 
3.12 
3.33 
3.66 
4.06 
5.91 

6.80 
9.35 
11.00 
13.35 
15.85 
20.25 

18 
19 
21U 
23  W 
25V4 
28'/4 

16V4 

n~A« 

19*4 

2U4 
23«» 
26 

12 
12 
12 
16 
16 
16 

n 
% 
% 

% 
% 

24 

12 

16 

••- 

The  above  list  is  for  fittings  drilled  in  accordance  with  SPIRAL  PIPE  STANDARD. 
These  fittings  are  also  furnished  flanged  and  drilled  in  accordance  with  A.  S.  M.  E.,  Standard  at  an 
additional  cost. 

Base  elbows  for  supporting  vertical  runs  furnished  as  ordered. 


•Flanges  Drilled. 

"Spiral  Pipe  Diameters.    Additional  price  charged  for  A.  S.  M.  E.  Standard  Diameters. 


The  discount  on  Spiral  Riveted  pipe  is  40!per  cent.     Galvanized  fittings  cost  15  per  cent,  more  than  the  net  price  of  ordinary  cast 
iron  or  flanged  fittings. 


142 


NOTES  ON  POWER  PLANT  DESIGN 


TABLE  OF  DIMENSIONS  OF 

*CARD  OR  FULL  WEIGHT  WROUGHT  IRON  OR 
STEEL  PIPE. 

For1  Steam,  Water  and  Gas. 


Nomi- 
nal 
Inside 
Diam. 
Ins. 

Actual 
Outside 
Diameter. 

Inches. 

Approx. 
Inside 
Diameter. 
Inches. 

Approx. 
Thick- 
ness. 
Inches. 

Length  of 
Pipe  per 
Sq.  Ft.  of 
Outside 
Surface. 
Feet. 

Inside 
Area. 
Inches. 

Length  of 
Pipe  Con- 
taining 
One 
Cu.  Ft. 
Feet. 

"Nomi- 
nal 
Weight 
per  Ft. 
Pounds. 

No.  of 

Threads 
per  Inch 
of 
Screw. 

Contents 
in 
***GaIs. 
per  Ft. 

% 

.405 

.270 

.068 

9.44 

.05681  2513. 

.24    |  27 

.0006 

V* 

.54 

.364 

.088 

7.075 

.1041|  1383.3 

.42    I  18 

.0026 

% 

.675 

.494 

.091 

5.657 

.19091    751.5 

.56 

18 

.0057 

Va 

.84 

.623 

.109 

4.547 

.3039]   472.4 

.85 

14 

.0102 

% 

1.05 

.824 

.113 

3.637 

.53331   270. 

1.12 

14 

.0230 

1 

1.315 

1.048 

.134 

2.903 

.8609]    166.9 

1.67 

11V6 

.0408 

1V4 

1.66 

1.380 

.140 

2.301 

1.496 

96.25 

2.24 

11V2 

.0638 

IVs 

1.90 

1.611 

.145 

2.010 

2.038 

70.65 

2.68 

11V2 

.0918 

2 

2.375 

2.067 

.154 

1.608 

3.355 

42.91 

3.61 

IH'2 

.1632 

2^ 

2.875 

2.468 

.204 

1.328 

4.780 

30.11 

5.74 

8 

.2550 

3 

3.50 

3.067 

.217 

1.091 

7.388 

19.49 

7.54 

8 

.3673 

3V6 

4.00 

3.548 

.226 

.955 

9.887 

14.56 

9.00 

8 

.4998 

4 

4.50 

4.026 

.237 

.849 

12.730 

11.31 

10.66 

8 

.6528 

4V2 

5.00 

4.508 

.246 

.765 

15.961 

9.03 

12.49 

8 

.8263 

5 

5.563 

5.045 

.259 

.687 

19.985 

7.20 

14.50 

8 

1.020 

6 

6.625 

6.065 

.280 

.577 

28.886 

4.98 

18.76 

Q 

1.469 

7 

7.625 

7.023 

.301 

.501 

38.743 

3.72 

23.27 

8 

1.999 

8 

8.625 

7.982 

.322 

.444 

50.021 

2.88 

28.18 

8 

2.611 

9 

9.625 

8.937 

.344 

.397 

62.722 

2.29 

33.70 

8 

3.300 

10 

10.75 

10.019 

.366 

.355 

78.822 

1.82 

40.00 

8 

4.081 

12 

12.75 

12.000 

.375 

.299    1113.098 

1.270!    49.00 

8 

5.87 

"MERCHANT  WEIGHT"  WROUGHT  IRON  OR 
STEEL  PIPE. 

8-INCH,  10-INCH,  12-INCH  SIZES. 


Nomi- 
nal 
Inside 
Diam. 
Ins. 

Actual 
Outside 
Diameter. 
Inches. 

Approx. 
Inside 
Diameter. 
Inches. 

Approx. 
Thick- 
ness. 
Inches. 

Length  of 
Pipe  per 
Sq.  Ft.  o< 
Outside 
Surface. 
Feet. 

Inside 
Area. 
Inches. 

Length  of 
Pipe  Con- 
taining 
One 
Cu.  Ft. 
Feet. 

"Nomi- 
nal 
Weight 
per  Ft. 
Pounds. 

No.  of 
Threads 
per  Inch 
of 
Screw. 

Contents 
in 
***GaIs. 
per  Ft. 

8 

8.625 

8.073 

.276 

.444 

51.187 

2.81 

25.00 

8 

2.659 

10 

10.750 

10.138 

.306 

.355 

80.715 

1.78 

35.00 

8 

4.190 

12 

12.750 

12.094 

.328 

.299 

114.875 

1.25 

45.00 

8 

5.967 

* EXTRA  STRONG  WROUGHT  IRON  OR  STEEL  PIPE.   *  DOUBLE  EXTRA  STRONG  WROUGHT  IRON  OR 


Length  of  Pipe 

'  al 

o 

iiacAi  i 

ircj. 

Inside 
Diam. 
Inches. 

Approx.  Inside 
Diameter. 
Inches. 

Actual  Outside 
Diameter. 
Inches. 

Approx. 
Thickness. 
Inches. 

per 
Square  Foot 
of  Outside 
Surface. 
Feet. 

Inside  Area. 
Square  Inches. 

Weight  per 
Foot. 
Pounds. 

Nominal 
Inside 
Diam. 
Inches. 

Approx.  Inside 
Diameter. 
Inches. 

Actual  Outside 
Diameter. 
Inches. 

Approx. 
Thickness. 
Inches. 

Length  of  Pipe 
per 
Square  Foot 
of  Outside 

Inside  Area. 
Square  Inches. 

"Nominal 
Weight  per 
Foot 

Vs 

.205 

.405 

.10 

9.433 

.033 

.29 

Feet. 

U 

.294 

.54 

.123 

7.075 

.068 

.54 

% 

.230 

.675 

220 

5.660 

.041 

.96 

% 

.421 

.675 

.127 

5.657 

.139 

.74 

tt 

.244 

.84 

.298 

4.547 

.047 

1.70 

tt 

.542 

.84 

.149 

4.547 

.231 

1.09 

% 

422 

105 

314 

3  637 

140 

*>  AA 

% 

.736 

1.05 

.157 

3.637 

.425 

1.39 

1 

.951 

1.315 

.182 

2.904 

.710 

2.17 

1 

.587 

1.315 

.364 

2.904 

.271 

3.65 

Hi 

1.272 

1.66 

.194 

2.301 

1.271 

3.00 

1% 

.885 

1.66 

.388 

2.304 

.615 

5.20 

IVi 

1.494 

1.90 

.203 

2.010 

1.753 

3.63 

Ufc 

1.088 

1.90 

.406 

2.010 

.930 

6.40 

• 

9  <W» 

502 

2»/2 

2.315 

2.875 

.280 

1.328 

4.209 

7.67 

3 

2.892 

3.50 

.304 

t       1.091 

6.569 

10.25 

2U 

1.755 

2.875 

.560 

1.328 

2.419 

13.68 

3% 

3.358 

4.00 

.321 

.955 

8.856 

12.47 

3 

2.284 

3.50 

.608 

1.091 

4.097 

18.56 

4 

3.818 

4.50 

.341 

.849 

11.449 

14.97 

y/2 

2716 

400 

642 

955 

5794 

2275 

41/2 

4280 

5.00 

.360 

.764 

14.387 

18.22 

5 

4.813 

5.563 

.375 

.687 

18.193 

20.54 

4 

3.136 

4.50 

.682 

.849 

7.724 

27.48 

6 

5.751 

6.625 

.437 

.577 

25.976 

28.58 

itt 

3.564 

5.00 

.718 

.764 

9.976 

32.53 

7 

6.625 

7.625 

.500 

.501 

34.472 

37:67 

5 

4.063 

5.563 

.75 

.687 

12.965 

38.12 

_ 

.  .« 

<!77 

9 

8.62 

9.62 

.500 

.397 

58.426 

48.25 

10 

9.75 

10.75 

.500 

.355 

74.662 

54.00 

7 

5.875 

7.625 

.875 

.501 

27.109 

62.38 

12 

11.75 

12.75 

.500 

.299 

108.430 

65.03 

8 

6.875 

8.625 

.875 

.443 

37.122 

71.62 

NOTES  ON  POWER  PLANT  DESIGN 


143 


DIMENSIONS  OF 

STANDARD  WEIGHT 
CAST  IRON  SCREWED  FITTINGS. 

For  Steam  Working  Pressures  up  to  125  Lbs. 


Size  Inches 

V< 

K 

% 

% 

1 

1% 

m 

2 

2% 

3 

3^2 

4 

41/2 

5 

6 

7 

8 

9 

10 

12 

A-Center  to  Face-Inches 

% 

7/8 

IVlG 

1%6 

1% 

1^6 

2 

2% 

2% 

"3%o 

3Hie 

4 

4%6 

4i%6 

5%0 

6M« 

6i%e 

7V3 

8% 

9%* 

AA-Face  to  Face.  Inches 

1% 

1% 

2% 

2% 

3 

3% 

4 

4% 

5% 

6% 

7% 

8 

8% 

9% 

10% 

12% 

13% 

15 

16% 

19% 

B-Center  to  Face-Inches 

%o 

%0 

Hie 

13/49 

*%e 

1%« 

194fl 

1% 

1% 

1% 

2%6 

2H 

2%6 

2»Ae 

2i%6 

3% 

3%6 

3% 

4%6 

4% 

C-Center  to  Face-Inches 

— 

1%6 

1% 

2%a 

2i/2 

3 

3% 

4 

5 

5% 

6% 

7% 

7% 

8^ 

9i%6 

11% 

12»9io 

14% 

16 

.__ 

D-Face  to  Face..  .Inches 

.._ 

2Wo 

2%o 

2% 

3% 

3% 

4% 

5% 

6!%6 

7% 

8% 

9% 

10% 

119ie 

13% 

14% 

16l%e 

19 

20% 

.-. 

X-Centerto  Back  )  T    . 
of  Thread-  1  Inches 

'% 

%0 

%e 

% 

% 

1% 

1%8 

,  1% 

1% 

2%6 

2% 

2% 

3%6 

3%o 

3»94o 

4%6 

5%6 

5% 

6% 

THie 

Y-CentertoBack  <  Tnrhp<. 
of  Thread-  (  lncnes 

%0 

% 

9ie 

% 

94  e 

% 

% 

% 

% 

% 

1 

1% 

19ie 

194. 

l%e 

1% 

l»94e 

2% 

2%6 

3 

Z-Centerto  Back  |  T    . 
of  Thread-  f  Inches 

1 

1% 

1% 

1% 

2%6 

2%6 

3% 

4 

4% 

5%6 

6 

6% 

7V4 

8%6 

9% 

11% 

12% 

14% 

... 

DIMENSIONS  OF 

EXTRA  HEAVY 

CAST  IRON  SCREW  FITTINGS. 

For  Steam  Working  Pressures  to  250  Lbs. 


331 


332 


333 


334. 


Size  Inches 

% 

% 

1 

1% 

1% 

2 

2% 

3 

3% 

4 

4% 

5 

6 

A-Center  to  Face  ._.  ._         Inches 

1%2 

1% 

P%2 

li%6 

2%6 

2% 

3 

3iMe 

4%2 

419sa 

42%2 

5%2 

5'%e 

AA-Face  to  Face  Inches 

2%6 

2% 

3%6 

3% 

4% 

5 

6 

7% 

SVie 

8»94« 

9»%e 

10%a 

11% 

B-Center  to  Face  •_  Inches 

% 

% 

1 

l%a 

1% 

1% 

1% 

2% 

2%6 

2»Ma 

2% 

3% 

3%e 

E-Outside  Diameter  of  Bead—Inches 

12%2 

P%2 

2%6 

2% 

3%6 

3% 

4%e 

5% 

6 

6^0 

7% 

7i94« 

9%e 

... 

F-Width  of  Bead                     Inches 

%6 

% 

%e 

^6 

% 

% 

1 

1% 

194e 

!7/ie 

!9/is 

PM*1 

1% 

G-Thread  Length  Inches 

9/ia 

% 

^6 

1%6 

% 

1 

1% 

1% 

1%6 

1%6 

1^6 

I1%e 

1% 

X-Centerto  Back  of  Thread..  Inches 

18/82 

% 

2%a 

1% 

194« 

1% 

2 

2^6 

2Me 

2%6 

2»94o 

3s/la 

3»94e 

•Y-Ctnter  to  Back  of  Thread.  .Inches 

94« 

% 

9ia 

% 

% 

y2 

% 

« 

1 

1% 

194« 

19ie 

1%6 

— 

144 


NOTES  ON  POWER  PLANT  DESIGN 


STANDARD  WEIGHT. 
CAST  IRON  SCREWED  FITTINGS. 

125  Lbs.  Working  Pressure. 


STRAIGHT 
ELBOWS. 


REDUCING 
ELBOWS. 


Size...  ..Inches 

% 

% 

J/2 

% 

1 

IVi 

I1/!- 

2 

21/2 

3 

Size  Inches 

% 

% 

% 

1 

1% 

IV2 

2 

2% 

3 

3M- 

Fig.  11,  R.  H  Each 

.05 

.05 

.06 

.08 

.10%  |   .16 

.20 

.28 

.50 

.75 

Fig.  13-...     Each 

.06 

.07 

.09 

.12 

.18 

.23 

.32 

.60 

.85 

1.20 

R.  H.  Galvanized...  Each 

.10 

.10 

.12 

.16 

.21 

.32 

.40 

.56 

1.00 

1.50 

Galvanized  Each 

.12 

.14 

.18 

.24 

.36 

.46 

.64 

1.20 

1.70 

2.40 

Fig.  12,  R.  and  L.-.-Each 

.06     .06 

.07 

.09 

.12 

.18 

.23 

.32 

.60 

.85 

Size  Inches 

4 

41/2 

5 

6 

7 

8 

9 

10 

12 

Size  ..Inches 

31/2 

4 

4M> 

5 

6 

7 

8 

9     |    10 

12 

Fig.  13  Each 

1.40 

2.00 

2.30 

3.15 

5.40 

7.75 

10.50 

15.50 

23.00 



Fig.  11,  R.  H  Each 

1.05 

1.20 

1.75 

2.00 

2.75 

4.70 

6.75 

9.00  1  13.50  1  20.00 

Galvanized  Each 

2.80  |  4.00  |  4.60  |  6.30  1  10.80 

15.50 

21.00  |  31.00  1  46.00  1  ._-. 

R.  H.  Galvanized.  ..Each 

2.10 

2.40 

3.50 

4.00 

5.50 

9.40 

13.50 

18.00 

27.00 

40.00 

- 

For  Elbows  tapped  left  hand  use  Right  and  Left  Elbow  List. 

Right  and  Left  Hand  Elbows  have  ribs  on  the  band  of  the  end  that  is  tapped  left  hand. 

ELBOWS  45°. 


SIDE  OUTLET 
ELBOWS. 


Size  .Inches 

J/i 

% 

% 

% 

1 

11/4 

1* 

2 

2'/2 

3 

Size  Inches 
Fig  22               Each 

J/2 

18 

% 
24 

1 
30 

U4 

48 

Hi 

60 

2 
84 

2i/2 
150 

3 

225 

31/2 

3  15 

Galvanized  Each 

.12 

.12 

.14 

.20 

.24 

.19 

.38 

.48 

.68 

1.20 

1.80 

Galvanized  Each 

.36 

.48 

.60 

.96 

1.20 

1.68 

3.00 

4.50 

6.30 

Size  ...Inches 

3'/2 

* 

41/2 

5 

6 

7 

8 

9 

10 

12 

Size  Inches 

4 

4'/i! 

5 

6 

7 

8 

9 

10 

12 

Fig.  21  ..Each 

1.25 

1.45 

2.20 

2.50 

3.45 

5.90 

8.50 

11.25 

17.00 

25.00 

Fig.  22..-  Each 

3.60 

5.25 

6.00 

8.25 

14.00 

2000 

26.00 

40.00 

60.00 

Galvanized  Each 

2.50 

2.90 

4.40 

5.00 

6.90 

11.80 

17.00 

22.50 

34.00 

50.00 

Galvanized  Each 

7.20 

10.50 

12.00 

16.50 

28.00 

40.00 

52.00 

80.00 

120.00 

STRAIGHT 
TEES. 


REDUCING 
TEES. 


Size      Inches 

V4 

% 

K 

% 

1 

Hi 

1% 

2 

21/2 

3    i 

Size             ..Inches 

:"» 

'/2 

% 

1 

l'/4 

1% 

2 

21/2 

3 

3% 

Fig.  31  Each 

.08 

.08 

.09 

.12 

.15 

.23 

.29 

.41 

.73 

1.10 

Fig  32                Kadi 

.09 

.10 

.14 

.17 

.27 

.33 

.47 

.83 

1.25 

1.75 

Galvanized  Each 

16 

Ifi 

IS 

?4 

.30 

.46 

.58 

.82 

1.46 

2.20 

Galvanized  Each 

.18  |  .20 

.28 

.34  |  .54 

.66 

.94 

1.66 

2.50 

3.50 

Size  .Inches 

31/2 

4 

4M> 

5 

6 

7 

8     |     9 

10 

12 

Size          —  -Inches 

4 

4% 

5 

6 

7 

8 

9 

10 

12 

Fig.  31  -Each 

1.50 

1.75 

2.55 

3.00 

4.00 

6.80 

9.75 

13.00 

19.50 

29.00 

Fig.  32  Each 

2.00 

2.95 

3.50 

4.60 

7.80  |  11.25 

15.00 

22.50 

33.50 

Galvanized  Each 

300 

350 

510 

600 

800 

13.60 

19.50 

26.00 

39.00 

58.00 

Galvanized  .  .  .  Each 

4.00 

5.90 

7.00  1  9.20  1  15.60  1  22.50 

30.00 

45.00 

67.00 

The  largest  opening  of  Reducing  Fittings  determines  the  list  price. 


STRAIGHT                                                                                REDUCING 
SIZES.                                                                                        SIZES. 

Size  Inches 

% 

J/2 

% 

1 

Hi 

1V2 

2 

2V2 

3 

3M> 

Size                 Inches 

i/> 

% 

1 

HA 

iys 

2 

21/2 

3 

•31/2 

Fig.  51.-    .—Each 

.15 

.16 

.22 

.27 

.42 

.53 

.75 

1.30 

2.00 

2.70 

Fig.  52  Each 

.18 

.25 

.30 

.46 

.60 

.83 

1.45 

2.20 

3,00 

Galvanized    ..  Each 

.30 

.32 

.44 

.54 

.84 

1.06 

1.50 

2.60 

4.00 

5.40 

Galvanized  Each 

.36 

.50 

.60    |   .92 

1.20 

1.66 

2.90 

4.40 

6.00 

Size  -.  Inches 

4 

41/2 

5 

6 

7 

8 

9 

10 

12 

Size                 Inches 

4 

4tt 

5 

6 

•   7 

8 

9 

10 

12 

Fig.  51          -  .Each 

3.15 

4.60  |   5.50 

7.25 

12.25 

17.50 

23.50 

35.00 

52.50 



Fig  52               Each 

3.50 

5.10 

6.00 

8.00 

13.50 

19.25 

26.00 

38.50 

58.00 

Galvanized  Each 

6.30 

9.20 

11.00 

14.50 

24.50 

35.00 

47.00 

70.00 

105.00 



Galvanized  Each 

7.00 

10.20 

12.00 

16.00 

27.00 

38.50  |  52.00 

77.00 

116.00 

REDUCING 
COUPLINGS. 

REGULAR  PATTERN, 


The  largest  opening  of  Reducing  Fittings  determines  the  list  price. 

ECCENTRIC 

REDUCING 

COUPLINGS. 


Size  ...Inches 

2 

21/2 

3 

31/2 

4 

41/2 

5 

6 

7 

8 

9 

10 

12 

Fig.  61..  .Each 

.43 

.60 

.80 

1.00 

1.35 

1.85 

2.00 

2.70 

5.35 

6.75 

8.35 

10.00 

15.00 

Galvanized  ... 

.86 

1.20 

1.60 

2.00 

2.70 

3.70 

4.00 

5.40 

10.70 

13.50 

16.70 

20.00 

30.00 

Size  ...Inches 

1 

VA 

1V2 

2 

21/2 

3 

31/2 

4 

Fig.  62.  „  Each 

-.50 

.55 

.72 

1.00 

1.50 

2.40 

3.00 

4.00 

Size.,.  Inches 

4V2 

5 

6 

7 

8 

9 

10 

12 

Fig.  62.  ..Each 

5.00 

6.00 

8.00 

9.00 

11.00 

12.50 

14.00 

18.00 

The  largest  opening  of  Reducing  Fittings  determines  the  list  price. 
Discount  60  and  10 


NOTES  ON  POWER  PLANT  DESIGN 


145 


DIMENSIONS  OF 
EXTRA  HEAVY  CAST  IRON  FLANGED  FITTINGS. 

For  Steam  Working  Pressures  up  to  250  Lbs. 


1021 


1022 


1012 


Size  ..Inches 

U4 

1% 

2 

2V2 

3 

3% 

4 

4% 

5 

AA-Face  to  Face  

8% 

9 

10 

11 

12 

13 

14 

15 

16 

A-Center  to  Face  

Wt 

4y2 

5 

5i/2 

6 

6% 

7 

7% 

8 

B-Centerto  Face  

4% 

4y2 

5 

5% 

6 

6V2 

7 

7% 

8 

C-Center  to  Face 

6% 

7 

7% 

8% 

9 

9% 

ioy4 

D-Radius  ... 

5% 

5% 

61/4 

67/8 

7% 

7% 

8% 

E-Center  to  Face  ^ 

2% 

2% 

3 

3i/2 

3% 

4 

4% 

4% 

5 

Size  _       __  .  .Inches 

6 

7 

8 

9 

10 

12 

14 

15 

16 

AA-Face  to  Face  

17 

18 

20 

21 

23 

26 

29 

30 

32 

A-Ceriter  to  Face  

81/2 

9 

10 

101/2 

111/2 

13 

14% 

15 

16 

B-Center  to  Face  

8% 

9 

10 

101/2 

111/2 

13 

14% 

15 

16 

C-Center  to  Face  

11% 

12% 

14 

15^4 

161/2 

19 

21% 

22% 

24 

D-Radius  . 

9% 

107/8 

12 

13 

141/8 

161/2 

18% 

20 

21V4 

E-Center  to  Face  

5% 

6 

6 

61/2 

7 

8 

8 

8% 

9 

All  Reducing  Fittings,  1*4  inches  to  9  inches  inclusive,  are  the  same  dimensions,  Center 
to  Face,  as  straight  sizes.  For  Dimensions  of  Reducing  Fittings  10  inches  and  larger, 
see  lower  table. 


Size  Inches 

10     |     12     |     14 

15 

16 

18 

20 

22 

24 

Size  of  Outlets 

6  and 
Smaller 

8  and 
Smaller 

9  and 
Smaller 

9  and 
Smaller 

10  and 
Smaller 

12  and 

Smaller 

14  and 
Smaller 

15  and 
Smaller 

15  and 

Smallei 

AA-Face  to  Face  of  Run 

18 

21 

22 

23 

24 

27 

30 

30 

30 

A-Center  to  Face  of  Run 

9 

10% 

11 

11% 

12 

13% 

15     |    15 

15 

B-Cen.to  Face  of  Outlet  |    11 

12% 

13% 

13% 

15 

16% 

17% 

18% 

19% 

146 


NOTES  ON  POWER  PLANT  DESIGN 


Straight  Tee. 


EXTRA  HEAVY. 
CAST  IRON  FLANGED  FITTINGS. 

250  Lbs.  Working  Pressure. 

Reducing  Tee. 


Long  Radius  Elbows. 


FIGURE  1011. 

FIGURE  1012. 

Size. 
Inches. 

Faced  Only. 
Each. 

Faced  and 
Drilled. 
Each. 

Diameter  of 
Flanges. 
Inches. 

Radius. 
Inches. 

Center  to 
Face. 
Inches. 

Size. 
Inches. 

Faced 
Only. 
Each. 

Faced 
and 
Drilled. 
Each. 

Center 
to 
Face. 
Inches. 

Face 
to 
Face. 
Inches. 

Diam. 
of 
Flanges. 
Inches. 

Size. 
Inches. 

Faced 
Only. 
Each. 

Faced 
and 
Drilled. 
Each. 

Center     Face 
to           to 
Face.       Face. 
Inches.    Inches. 

2 

9.50 

11.50 

6% 

5% 

6% 

2 

7.00 

8.50 

5 

10 

61/2 

2 

8.00 

9.50 

For  Dimensions,  see  page  JOT, 

2% 

10.00 

12.50 

TV* 

5% 

7 

2% 

7.25 

9.00 

5% 

11 

7V2 

2V2 

8.25 

10.00 

3 

11.50 

14.00 

8V4 

6% 

7% 

0 

8.25 

10.00 

6 

12 

8V4 

3 

9.50 

11.25 

3% 

13.00 

15.50 

9 

6% 

8% 

3% 

9.50 

11.25 

6% 

13 

9 

3% 

11.00 

12.75 

4 

14.50 

18.50 

10 

7% 

9 

4 

10.50 

13.50 

7 

14 

10 

4 

12.00 

15.00 

4% 

18.00 

22.00 

10% 

7% 

9% 

4% 

13.00 

16.00 

7% 

15 

10% 

4V2 

15.00 

18.00 

5 

19.50 

23.50 

11 

8V2 

ioy* 

5 

14.25 

17.25 

8 

16 

11 

5 

16.25 

19.25 

6 

24.00 

28.00 

12V2 

9% 

11% 

6 

17.50 

20.50 

8V2 

17 

12% 

6 

20.00 

23.00 

7 

32.00 

39.50 

14 

10% 

12% 

7 

23.00 

28.75 

9 

18 

14 

7 

26.50 

32.00 

8      i    29.00 

34.75 

10 

20 

15 

8 

33.50 

39.00 

8 

40.00 

47.50 

15 

12 

14 

9 

38.00 

44.00 

101/2 

21 

16'/i 

9 

43.50 

50.00 

9 

52.00 

60.00 

16V4 

13 

l5Vi 

10 

46.50 

52.50 

11% 

23 

17% 

10 

53.50 

60.00 

10          |           64.00 

72.00 

17% 

14% 

16% 

12 

64.00 

73.00 

13 

26 

20 

12 

74.00 

83.00 

12 

88.00 

100.00 

20 

16% 

19 

14 

84.00 

95.00 

141/2 

29 

22V2 

14 

96.00 

107.00 

14 

116.00 

130.00 

22% 

18% 

21% 

15 

105.00 

117.00 

15 

30 

23% 

15 

120.00 

132.00 

15 

144.00 

160.00 

23% 

20 

22% 

16 

122.00 

135.00 

16 

32 

25 

16 

140.00 

153.00 

16 

168.00 

186.00 

25 

21V4 

24 

90°  Elbow. 


45°  Elbow. 


Straight  Cross. 


Reducing  Cross. 


FIGURE  971. 

FIGURE  972. 

FIGURE  1021. 

FIGURE  1022. 

Size. 
Inches. 

Faced 
Only. 
Each. 

Faced  and 
Drilled. 
Each. 

Center  to 
Face. 
Inches. 

Size. 
Inches. 

Faced 
Only. 
Each. 

Faced  and 
Drilled. 
Each. 

Center  to 
Face. 
Inches. 

Diam.  of 
Flanges. 
Inches. 

Size. 
Inches. 

Faced 
Only. 
Each. 

Faced 
and 
Drilled. 
Each. 

Center 

Face. 
Inches. 

Face 
to 
Face. 
Inches. 

Diam. 
of 
Flanges. 
Inches. 

Size. 
Inches. 

Faced 
Only. 
Each. 

Faced 
and 
Drilled. 
Each. 

Center     Face 
to           to 
Face.      Face. 
Inches.    Inches. 

2 

4.75 

5.75 

5 

2 

5.25 

6.25 

3 

6% 

2 

9.50 

11.50 

5 

10 

6% 

2 

11.00 

13.00 

For  Dimensions,  see  page  1 

2% 

5.00 

6.25 

5% 

2% 

5.50 

6.75 

3% 

7% 

2% 

10.00 

12.50 

5% 

11 

7'/2 

2% 

11.50 

14.00 

3 

5.75 

7.00 

6 

3 

6.25 

7.50 

3% 

8V4 

3 

11.50 

14.00 

6 

12           8Vi 

3 

13.25 

15.75 

3% 

6.50 

7.75 

6% 

3% 

7.25 

8.50 

4 

9 

3% 

13.00 

15.50 

6% 

13 

9    ' 

3% 

15.00 

17.50 

4 

7.25 

9.25 

7 

4 

8.00 

10.00 

4% 

10 

4 

14.50 

18.50 

7 

14 

10 

4 

16.75 

20.75 

4% 

18.00 

22.00 

7% 

15 

10% 

4% 

20.75 

25.00 

4% 

9.00 

11.00 

7% 

4% 

10.00 

12.00 

4% 

10% 

5 

19.50 

23.50 

8 

16 

11 

5 

22.50 

26.50 

5 

9.75 

11.75 

8 

5 

10.75 

12.75 

5 

11 

6 

24.00 

28.00 

8% 

17 

12% 

6 

27.50 

31.50 

6 

12.00 

14.00 

8% 

6 

13.00 

15.00 

5% 

12% 

7 

32.00 

39.50 

9 

18 

14 

7 

37.00 

45.00 

7 

16.00 

19.75 

9 

7 

16.00 

19.75 

6 

14 

8 

40.00 

47.50 

10 

20 

15 

8 

46.00 

53.50 

8 

20.00 

23,75 

10 

8 

20.00 

23.75 

6 

15 

9 

52.00 

60.00 

10% 

21 

16V4 

9 

60.00 

68.00 

9 

26.00 

30.00 

10% 

9 

26.00 

30.00 

6% 

16V4 

10 

64.00 

72.00 

11% 

23 

17% 

10 

74.00 

82.00 

10 

32.00 

36.00 

11% 

10 

32.00 

36.00 

7 

171/2 

12 

88.00 

100.00 

13 

26 

20 

12 

100.00 

112.00 

14 

116.00 

130.00 

14% 

29 

22% 

14 

132.00 

146.00 

12 

44.00 

50.00 

13 

12 

44.00 

50.00 

8 

20 

15 

144.00 

160.00 

15 

30 

23% 

15 

165.00 

180.00 

14 

58.00 

65.00 

14% 

14 

58.00 

65.00 

8 

22% 

16 

168.00 

186.00 

16 

32 

25 

16 

193.00 

210.00 

15 

72.00 

80.00 

15 

15 

72.00 

80.00 

8% 

23% 

16 

84.00 

93.00 

16 

16 

84.00 

93.00 

9 

25 

Discount  on  all  Flanged  Fittings  60  per  cent. 


EXTRA  HEAVY. 
CAST  IRON  FLANGED  FITTINGS. 

250  Lbs.  Working  Pressure. 

Reducing  Taper  Elbows. 


Size. 
Inches. 

FIGURE  981. 

Diameter  of 
Flanges. 
Inches. 

Center 
to 
Face. 
Inches. 

Size. 
Inches. 

FIGURE  981. 

Diameter  of 
Flanges. 
Inches. 

Center 
to 
Face. 
Inches. 

Faced 
Each. 

Faced 
and 
Drilled. 
Each. 

Faced 
Each. 

Faced 
and 
Drilled. 
Each. 

2     xiy4 

9.50 

11.50 

6%X  5 

5 

7x  5 

32.00]    39.50 

14     x  11          9 

2     x  1% 

9.50 

11.50 

6%x   6 

5 

7x   6 

32.00 

39.50 

14     x  12%      9 

2%xl% 

10.00 

12.50 

7%x   6 

5% 

8x   4 

40.00 

47.50 

15     x  10        10 

2%x2 

10.00 

12.50 

7%X  ey2 

5% 

8x   5 

40.00 

47.50 

15     x  11        10 

3     x  1V2 

11.50 

14.00 

8%x   6 

6 

8x   6 

40.00 

47.50 

15     x!2%    10 

3     x2 

11.50 

14.00 

8%X     6% 

6 

8x   7 

40.00 

47.50 

15     x  14       10 

3     x  2% 

11.50  |  14.00 

8%x   7% 

6 

10  x   5 

64.00 

72.00 

17%  x  11        11% 

3%  x  2 

13.00  |  15.50 

9     x   0/6 

6% 

10  x   6 

64.00  |   72.00 

mix  12%    11% 

3%x2% 

13.00 

15.50 

9     x   7% 

6V2 

10  x   8 

64.00 

72.00 

17%  x  15       11% 

3%  x  3 

13.00 

15.50 

9     x   8% 

6% 

12  x   7 

88.00  1  100.00 

20     x  14        13 

4     x2 

14.50 

18.50 

10     x   6% 

7 

12  x   8 

88.00 

100.00 

20     x  15        13 

4     x  2% 

14.50 

18.50 

10     x   7% 

7 

12xx9 

88.00 

100.00 

20     x  16% 

13 

4     x3 

14.50 

18.50 

10     x   8% 

7 

12x10 

88.00 

100.00 

20     x  17% 

13 

4   x3% 

14.50 

18.50 

10     x   9 

7 

14  x   6 

116.00 

130.00 

22%xl2%|  14% 

5     x2% 

19.50 

23.50 

11     x   7% 

8 

14x10 

116.00 

130.00 

22%  x  17% 

14% 

5     x3 

19.50 

23.50 

11     x   8% 

8 

14x12 

116.00 

130.00 

22%  x  20 

14% 

5     x4 

19.50 

23.50 

11     xlO 

8 

15  x   6 

144.00 

160.00 

23%  x  12% 

15 

6     x3 

24.00 

28.00 

12V2  x   8y4 

8% 

15x10 

144.00 

160.00 

23%  x  17% 

15 

6     x  3% 

24.00 

28.00 

12%  x   9 

8% 

15x12 

144.00 

160.00 

23%  x  20 

15 

6     x4 

24.00 

28.00 

12%  x  10 

8% 

16x   8 

168.00 

186.00 

25     x!5 

16 

6     x  4% 

24.00 

28.00 

12%  x  10% 

8V2 

16x10 

168.00 

186.00 

25     x  17% 

16 

6     x5 

24.00 

28.00 

12%  x  11 

8V2 

16x12 

168.00 

186.00 

25     x20 

16 

7     x4 

32.00 

39.50 

14     xlO 

9 

16x14 

168.00 

186.00 

25     x  22% 

16 

Pipe  Size 
and  O.  D.  of 
Flange. 
Inches. 

Screwed  Flange. 

Blank  Flange. 

Price 
of  Bolts 
per  Set 
for  One 
Joint. 

Threading 
Pipe,  Making 
On  and 
Refacing, 
Not  Including 
Flange. 
Net  Each. 

Faced 
Only. 
Each. 

Faced 
and 
Drilled. 
Each. 

Faced 
Only. 
Each. 

Faced 
and 
Drilled. 
Each. 

1      x    4% 

1.00 

1.25 



.20 

.60 

l%x   5 

1.05 

1.35 

. 



.20 

.60 

l%x   6 

1.10 

1.40 





.25 

.65 

2     x    6% 

1.20 

1.50 

1.40 

1.70 

.25 

.70 

2%x   7% 

1.40 

2.00 

1.60 

2.20 

.40 

.75 

3     x   8% 

1.60 

2.25 

1.85 

2.50 

.55 

.85 

3%'x   9 

1.80 

2.50 

2.10 

2.80 

.55 

.90 

4     xlO 

2.15 

3.00 

2.50 

3.35 

.80 

.95 

4%  x  10% 

2.50 

3.35 

2.30 

3.75 

,.80 

1.00 

5     xll 

2.80 

3.65 

3.25 

4.10 

•    .80 

1.10 

6     x!2% 

3.20 

4.00 

3.70 

4.50 

1.15 

1.25 

7     x!4 

4.35 

5.75 

5.00 

6.40 

1.80 

1.35 

8     x!5 

5.00 

6.50 

5.75 

7.25 

1.80 

1.55 

9     x  16% 

6.75 

8.25 

7.75 

9.25 

1.80 

1.80 

10     x  17V2 

7.75 

9.25 

9.00 

10.60 

2.60 

2.00 

12     x20 

10.50 

12.50 

14.00 

16.00 

2.75 

2.75 

14     x  22% 

13.75 

16.00 

17.50 

19.75 

3.60 

3.50 

15     x  23% 

18.00 

21.00 

22.50 

25.50 

4.75 

3.75 

16     x25 

22.50 

26.00 

28.00 

31.50 

4.75 

4.75 

18     x27 

27.50 

31.00 

33.00 

36.50 

5.60 

7.00 

20     x  29% 

30.00 

34.00 

36.00 

40.00 

aso 

8.25 

22     x  31% 

33.75 

39.00 

41.00 

46.00 

10.00 

9.50 

24     x  34% 

41.00 

46.00 

50.00 

55.00 

10.00 

11.00 

Discount  on  all  Flanged  Fittings  60  per  cent. 


EXTRA  HEAVY. 
CAST  IRON  SCREWED  FITTINGS. 

250  Lbs.  Working  Pressure. 
FLANGE  UNIONS. 


Size. 
Inches. 

Diameter  of 
Flanges. 

Diameter  of 
Bolt  Circle. 

Number  of 
Bolts. 

Price. 
Each. 

% 

3 

2 

4 

.60 

% 

3% 

2%                        4 

.70 

1 

3% 

2% 

4 

.80 

iy* 

4% 

3% 

4 

1.00 

1% 

4% 

3% 

4 

1.15 

2 

5% 

4% 

5 

1.50 

2% 

6% 

4% 

5 

1.90 

3 

6T/8 

5% 

6 

2.25 

3% 

7% 

6 

6 

2.70 

4 

8 

6%                        7 

3.15 

4V2 

8% 

7% 

8 

4.00 

5 

9% 

7% 

8 

4.75 

6 

10% 

9% 

9 

6.00 

7. 

12 

ioy* 

10 

8.25 

8 

13% 

11% 

10 

10.50 

LONG  SWEEP  FITTINGS. 
CAST  IRON. 

For  Steam  Working  Pressures  to  125  Lbs. 
For  Water  Working  Pressures  to  175  Lbs. 

A 

T 
DOUBLE  SWEEP 

TEES. 


291 


Size  Inches 

1 

1V4 

1% 

2     |   2%   |     3     |   3%  |     4 

Fig.  291,  Tees...  Each 

.64 

.80 

1.10 

1.60  |  2.40  |  4.50  |  6.50  |    7.00 

Reducing  Tees      Each 

.96 

1.20 

1.65 

2.40  |  3.60  |  6.75  |  9.75  |  10.50 

A-Center  to  Face  Inches 

2% 

2% 

3 

3%   |   4%   |  5%  |  5%   |    6% 

Size  Inches 

4% 

5 

6 

7     |     8     |     9     |    10    |    12 

Fig.  291,  Tees  ..Each  1  11.00  1  13.00  1  17.50  1  26.00  |  34.00  1  51.00  1  60.00  |  80.00 

Reducing  Tees  Each 

16.50  1  19.50  |  26.25  1  39.00  |  51.00  1  76.50  1  90.00  |l20.00 

A-Center  to  Face  Inches 

6V4  1     7     |  7% 

8%  1   9%   |  10%  I  11%  |  12% 

EXTRA  LONG  SWEEP 
ELBOWS. 


B 


\ 


Size  »-  Inches 

1 

1V4 

1% 

2 

2% 

3 

3% 

4 

Fig.  292,  Elbows  .-•-..  Each  |   .50 

.70 

.90 

1.20 

2.00 

3.00 

4.00 

5.00 

B-Center  to  Face  .  .  I  Inches 

3tte 

3% 

4 

5% 

6% 

7V4 

8V4   |  10% 

C-Radius  Inches 

2% 

2% 

3% 

4% 

5Y4 

5% 

6% 

9% 

Size...  Inches 

4% 

5 

6 

7 

8 

9 

10 

12 

Fig.  292,  Elbows  Each 

7.00  1   9.00 

13.TX)  1  20.00  1  28.00 

34.00 

40.00  1  60.00 

B-Center  to  Face  Inches 

10% 

11% 

13 

14% 

18V4 

21% 

24% 

31 

C-Radius  Inches 

9% 

9% 

11% 

12% 

16% 

198/4 

22% 

28% 

Straight  sizes  furnished  galvanized  at  double  the  above  lists,  and  regular  discounts. 


Discount  60  and  10 


NOTES  ON  POWER  PLANT  DESIGN 


149 


DIMENSIONS  OF 

MEDIUM  PRESSURE 
GATE  VALVES. 


Fig.  1521.     Screwed. 


B  — 4 
Fig.  1522.    Flanged. 


Size  

Ins 

2 

2V2 

3 

3% 

4 

4V2 

5 

6 

A-Fig.  1521  

Ins. 

Si/a 

6    • 

7V4 

71/2 

7% 

8% 

8V2 

8% 

B-Fig.  1522  

Ins 

7% 

8 

9% 

10 

10% 

11 

11% 

12 

C-Center  to  Top  of  Wheel 

Ins. 

11% 

12V2 

15 

16% 

19 

20 

22 

2sy4 

D-Center  to  Top  of  Spindle,  Open  .Ins. 

14 

15V2 

18% 

20% 

23% 

25 

28 

32 

E-Diameter  of  Wheel  

Ins. 

6% 

6% 

7% 

7% 

9 

9 

10 

12 

F-Diameter  of  Flange  _ 

_  Ins. 

6% 

7'/2 

8% 

9 

10 

10% 

11 

i2y2 

G-Thickness  of  Flange    . 

Ins. 

% 

1 

1% 

1%6 

l]/4 

1%6 

1% 

1%6 

Size  

Ins. 

7 

8 

9 

10 

12 

- 

B-Fig.  1522 

Ins. 

12V2 

13% 

14 

15 

16 

__... 

..,- 

— 

C-Center  to  Top  of  Wheel 

Ins. 

28 

32 

34 

39 

44 

D-Center  to  Top  of  Spindle,  Open  _  Ins. 

36 

41 

44 

50 

57 

E-Diameter  of  Wheel 

Ins. 

12 

14 

14 

16 

18 

F-Diameter  of  Flange 

Ins 

14 

15 

16V4 

17% 

20 

G-Thickness  of  Flange 

Ins. 

1% 

1% 

1% 

1% 

2 

Size  Inches        2 

!          2%         3 

3Va 

4 

4% 

5 

6 

Fig.  1521  Each     23 

00     25.00     29.00 

35.00  |  40.00 

50.00 

54.00 

65.00 

Fig.  1522  Each     25 

50     27.50     32.00 

38.00 

45.00 

55.00 

59.00 

72.00 

Drilling  ."  Each       .7 

5         .75         .75 

1.00 

1.25 

1.50 

1.50 

1.75 

Size  .  .Inches        7 

*8          9 

10 

12 





Fig.  1522  __  Each     97 

00    117.00   152.00 

178.00 

225.00 

.... 

.... 

Drilling  Each       2 

25       2.25       2.50 

2.50 

3.50 

.... 

.... 

This  valve  is  suitable  for  pressure  up  to  175  Ibs. 
The  discount  is  50  and  5  per  cent. 


150 


NOTES  ON  POWER  PLANT  DESIGN 


OUTSIDE  SCREW 

AND 
YOKE  GATE  VALVES. 


Fig.  1581. 


Size  

Inche 

s 

21/2 

3 

3i/2 

4 

4!/2 

5 

6 

A-Fig.  1581-     . 

Inche 

s 

8% 

91/2 

11% 

12% 

14 

.15% 

16i/i 

B-Fig.  1582  

Inche 

s 

9V2 

11% 

117/S 

12 

13% 

15 

15% 

C-Center  to  Top  

Inche 

s 

13% 

15% 

17% 

18% 

23% 

23% 

25% 

D  Center  to  Top  of  Stem,  Ope 

n           Inche 

s 

16V* 

18% 

21 

23% 

29V4 

29% 

31% 

E-  Diameter  of  Wheel  

_     Inche 

s 

8 

10 

10 

11 

11 

12 

13 

F-Diameter  of  Flange 

Inche 

s 

7VL> 

8V4 

9 

10 

101/2 

11 

12V2 

G-Thickness  of  Flange 

_  Inche 

5 

1 

IH 

!3/i« 

P/4 

!5/ie 

1% 

17/10 

Size  

Inche 

s 

7 

8 

9 

10 

12 

B-Fig.  1582  . 

Inche 

5 

16% 

16i/2 

17 

18 

19% 

C-Center  to  Top  ... 

Inche 

S 

29% 

32i/2 

361/2 

39% 

45% 

D-Center  to  Top  of  Spindle,  Open,..  Inches 

37i-t> 

41% 

46V2 

50y3 

58  '/2 

E-  Diameter  of  Wheel  . 

Inche; 

15 

15 

16 

16 

18 

F-Diameter  of  Flange- 

Inche; 

14 

15 

*16V4 

17'/2 

20 





G-Thickness  of  Flange  .  _  . 

Inches 

1% 

1% 

1% 

.1% 

2 

Size                        Inches       21 

4            3 

3V2 

4 

4% 

5 

6 

Fig.  1581  .               Each      41 

00       54.00 

67.00 

72.00 

92.00 

100.00 

115.00 

Fig.  1582  .               Each      43. 

50       57.00 

70.00 

77.00 

97.00 

105.00 

122.00 

Drilling  ..Each 

75           .75 

1.00 

1.25 

1.50 

'  1.50 

1.75 

Size                        Inches         7 

*8 

9 

10 

12 

.... 



Fig.  1582  ...            Each  |  147 

.00     187.00 

257.00 

283.00 

390.00 



Drilling  T.Each         2 

.25         2.25 

2.50 

2.50 

3.50 

Discount  60  per  cent. 


NOTES  ON  POWER  PLANT  DESIGN 


151 


DIMENSIONS  OF 

EXTRA  HEAVY  GATE  VALVES. 

WITH  BY-PASS. 


Size  

.Inches 

6 

7 

8 

9 

•  10 

Face  to  Face,  Flanged 

Inches 

15% 

16% 

16%          17 

18 

C-Center  to  Top 

Inches 

25% 

29% 

321/2        36% 

39% 

E-Diameter  of  Wheel 

.  Inches 

13            15 

15           16 

16 

D-Center  to  Top  of  Spindle,  open_. 

.Inches 

32            38 

41           46 

50 

H-Center  to  Outside  of  By-  Pass.  _- 

-Inches 

14 

15 

16          16% 

17% 

Diameter  of  Flange  . 

.Inches 

121/2          14 

15          16% 

17% 

Thickness  of  Flange    

.Inches 

F/io         1% 

1%          1% 

1% 

Size  of  By-Pass.  

-Inches  |     1%          1%          1%          \Vz 

1V2 

Size...  __ 

-Inches  |      12            14            15 

16 

Face  to  Face,  Flanged  

.Inches  |     19%        21%        22V-!          24 

C-Center  to  Top  

Inches 

45% 

50%        521/2 

58          ..-. 

E-Diameter  of  Wheel  

-Inches  |      18            22            22            24 

D-Centerto  Top  of  Spindle,  open.  __  Inches 

58%    1      66           69 

751/2 

H-Center  to  Outside  of  By-Pass  Inches  |      20      |      21 

21% 

27 

Diameter  of  Flange  

-Inches  |      20      |    22%        23%- 

25 

Thickness  of  Flange  ' 

-Inches 

2            2Vs         2a/i« 

2'/4 

Size  of  By-  Pass  .-     _ 

.Inches  |       2 

2             2 

3 

Size               -     .Inches 

*6 

7 

8 

9 

10 

12 

Fig.  1601  Each 

170.00 

195.00 

240.00 

310.00 

335.00 

45500 

Drilling  .-Each 

1.75 

2.25 

2.25 

2.50 

2.50 

3.50 

Size  Inches 

14 

15 

16 

Fig.  1601  Each 

580.00 

680.00 

825.00 

Drilling  Each 

4.00 

4.00 

5.00 

*  6-inch  Valves  have  Bronze  Spindles. 
Larger  sizes,  Steel  Spindles,  Nickel  Plated. 
Discount  60  per  cent. 


152 


NOTES  ON  POWER  PLANT  DESIGN 


DIMENSIONS  OF 

EXTRA  HEAVY 

IRON  BODY  GLOBE  AND  ANGLE  VALVES. 


k... ..£--> 


—  L-  —  1 

1 

f-  (        •        'i  ^ 

j 

—  j  —  L. 

.  j.    .. 

"i..       . 

Jr-                     1 

i 

j          ':' 

j 

F 

1981 


1982 


Size..       ._     .              Inches 

2y2  |    3 

3% 

4 

4y2 

5 

6 

A-End  to  End        ..               Inches 

10i/2 

11V2 

12% 

13 

14 

14% 

16% 

|  -Center  to  End  .  .                   Inches 

51/4 

5% 

6% 

6% 

7     |    7% 

8% 

B-Face  to  Face  Inches 

11% 

12% 

13% 

14 

15 

15% 

171/2 

TJ  -Center  to  Face                      Inches 

5% 

6% 

6% 

7 

7% 

77/8 

8% 

C-Center  to  Top,  Closed-.     .Inches 

13 

14 

15% 

16% 

17% 

18 

20 

D-Center  to  Top,  Open  .  .      Inches 

14% 

15% 

17% 

19         20    |  20% 

23% 

E-Diameter  of  Wheel      _        Inches 

8 

9 

9 

12         12 

14 

16 

F-Diameter  of  Flange   .          Inches 

7% 

8% 

9 

10       10% 

11 

12% 

G-Thickness  of  Flange             Inches 

1 

1% 

1%6 

1%          15/1C 

1% 

17/10 

Size  __  „            Inches 

7 

8 

10 

12 

-- 

B-Face  to  Face  .Inches 

19% 

21 

241/a 

28 

.  __ 

l[  -Center  to  Face                      Inches 

9% 

10% 

12% 

14 

C-Center  to  Top,  Closed  _  .      Inches 

21% 

25 

28 

32 

j 

1 

D-Center  to  Top,  Open         .  Inches 

25% 

29 

33 

38 

i 

1 

E-Diameter  of  Wheel..    _     _  Inches 

16 

20 

24 

30 

F-Diameter  of  Flange              Inches 

14 

15 

17% 

20 





G-Thickness  of  Flange        _.  Inches 

1% 

1% 

1%   |     2 

— 



Size  ] 

nchcs 

2% 

3      |     3% 

4 

Globe  or  Angle  Valves,  Screwed  Ends 

Each 

33.00 

37.00 

42.00 

46.00 

Globe  or  Angle  Valves,  Flanged  Ends 

Each 

35.00 

40.00 

45.00 

50.00 

Fig.  1981,  Drilling  _                  .            .  .     ...Each 

.75 

.75 

1.00 

1.25 

Fig.  1982,  Dialling  _                                            Each 

1.25 

1.25 

1.50 

1.75 

Size  I 

nches 

4y2 

'   5 

6 

Globe  or  Angle  Valves,  Screwed  Ends 

.Each 

56.00 

61.00 

75.00 



Globe  or  Angle  Valves,  Flanged  Ends 

.Each 

60.00 

65.00 

80.00 

Fig.  1981,  Drilling 

.Each 

1.50 

1.50 

1.75 



Fig.  1982,  Drilling 

.Each 

2.00 

2.00 

2.50 

Size  .....      I 

nches 

7 

8 

10 

12 

Globe  or  Angle  Valves,  Flanged  Ends 

Each 

100.00 

120.00 

200.00 

300.00 

Fig.  1981,  Drilling                   _.  

Each 

2.25 

2.25 

2.50 

3.5u 

Fig.  1982.  Drilling  ..                                       _.Each 

3.00 

3.00 

3.50 

5.00 

Discount  60  per  cent. 


NOTES  ON  POWER  PLANT  DESIGN 
DRILLING  TEMPLATES 

FOR 

FLANGED  VALVES,  FLANGED  FITTINGS  AND  FLANGES. 

250  Lbs.  Working  Pressure. 


153 


Size. 
Inches. 

Diameter  of 
Flanges. 

Thickness  of 
Flanges. 

Bolt 
Circle. 

Number  of 
Bolts. 

Size  of 
Bolts. 

Length  of 
Bolts. 

1 

VA 

*%« 

3% 

4 

% 

2 

1% 

5 

% 

3% 

4 

% 

2% 

1% 

6 

!%e 

4% 

*4 

% 

2% 

2 

6M 

% 

5 

4 

% 

2% 

2% 

TV* 

1 

5% 

4 

% 

3 

3 

8V4 

1% 

6% 

8 

% 

3 

3% 

9 

l%e 

7% 

8 

% 

3% 

4 

10 

IV* 

7% 

8 

% 

3% 

«M 

10% 

l%e 

8% 

8 

% 

3% 

5 

11 

1% 

9V* 

8 

% 

3% 

6 

12% 

1%6 

10% 

12 

% 

3% 

7 

14 

1% 

11% 

12 

% 

4 

8 

15 

1% 

13 

12 

% 

4% 

9 

16% 

1% 

14 

12 

1 

4% 

10 

17% 

1% 

15% 

16 

1 

4% 

12 

20 

2 

17% 

16 

.1 

5 

14 

22% 

2% 

20 

20 

1 

5V* 

15 

23% 

2%e 

21 

20 

1% 

5% 

16 

25 

2V4 

22% 

20 

1% 

5% 

18 

27                  2% 

24% 

24 

1% 

6 

20 

29% 

2% 

2694 

24 

1% 

6% 

22 

31% 

2% 

28% 

28 

1% 

6% 

24 

34% 

2% 

31V4 

28 

1%       |         7 

I 

jdflj 

—  j 

Ins. 

3 

6 

4 

Xv 

5 

!x\. 

Size  Base  Ins. 
Floor  to  Center  of  Pipe-Ins. 
Each  

6%x6% 
4»W« 
L50 

7x7 
5%. 
L75 

7x7 

5% 
1.90 

8x8 
6 

2.25 

8x8 
6% 
2.40 

10x10 
8. 
3^5 

1  Size  Base  Ins.  | 
Floor  to  Center  of  Pipe-Ins. 
Each                    ~ 

14 
10% 

14 

11%0 

14 

12%. 

19 
15% 

19 

16% 

15 
19 

16% 

14.50 

From  Wall  to  Center  of  Pipe,  Adjustable 

Inches 

15  to  19 

Horizontal  Center  between  Wall  Bolts 

g 

Vertical  Center  between  Wall  Bolts 

Inches 

18% 

From  Wall  to  End  of  Bracket      . 

.....  -Inches 

27 

Price,  including  Wall  Bolts 

Each 

28.00 

Number 

1  —  —  — 

Pipe 
5 
6 
~T~ 
8 

Wall  to  Center  of  Pipe.Ins. 
Each..... 
Each  .... 
Each~ 
Each  ___"                      !      | 

6to9 
17.00 
17.50 

18.00 

iaoo 

9  to  12 
18.00 
1830 
19.00 
19.00 

12  to  15 
18.50 
19.00 
1950 
1950 

2 

15  to  16 
19.00 
19.50 
20.00 
20.00 

3 

18  to  21 
19.50 
20.00 
20.50 
20.50 

:>i 
1 
1 

•> 

? 

9 
10 
12 
1*~ 

Each  
Each  
Each  
Each  

18.50 
18.50 
19.00 
20.00 

19.50 
19.50 
21.00 
22.00 

20.00 
20.00 
21.50 
22.50 

20.50 
2050 
22.00 
23.00 

21.00 
21.00 
23.00 
23.50 

? 
1 
1 

B 

Discount  on  Cast  Iron  Rolls,  Chains  and  Wall  Brackets  37 ^  per  cent. 


154 


NOTES  ON  POWER  PLANT  DESIGN 


SEAMLESS  DRAWN  BRASS  PIPE. 

STANDARD  IRON  PIPE  SIZES. 


Iron 
Pipe 
Sizes. 

Actual 
Outside 
Diameter. 

Actual 
Inside 
Diameter. 

Approximate 
Wt.  per  Foot 
Pounds.' 

Iron 
Pipe 
Sizes. 

Actual 
Outside 
Diameter. 

Actual 
Inside 
Diameter. 

Approximate 
Wt.  per  Foot 
Pounds.* 

Vs 

.405 

.281 

.25 

2V» 

2.875 

2.5 

5.75 

y* 

.540 

.375 

.43 

3 

3.500 

3.062 

8.30 

% 

.675 

.494 

.62 

3Va 

4.000 

3.5 

10.90 

V2 

.840 

.625 

.90 

4 

4.500 

4. 

12.70 

fc 

1.050 

.822 

1.25 

4y2 

5.000 

4.5 

13.90 

1 

1.315 

1.062 

1.70 

5 

5.563 

5.062 

15.75 

1% 

1.660 

1.368 

2.50 

6 

6.625 

6.125 

18.31 

1% 

1.900 

1.6 

3.00 

7 

7.625 

7.052 

23.73 

2     , 

2.375 

2.062 

4.00 

8 

8.620 

7.980 

29.88 

EXTRA  HEAVY  IRON  PIPE  SIZES. 


Iron 
Pipe 
Sizes. 

Actual 
Outside 
Diameter. 

Actual 
Inside 
Diameter. 

Approximate 
Wt.  per  Foot 
Pounds.* 

Iron 
Pipe 
Sizes. 

Actual 
Outside 
Diameter. 

Actual 
Inside 
Diameter. 

Approximate 
Wt.  per  Foot 
Pounds.* 

Vs 

.405 

.205 

.370 

2 

2.375 

1.933 

5.460 

V* 

.540 

.294 

.625 

2% 

2.875 

2.315 

8.300 

% 

.675 

.421 

.830 

3 

3.500 

2.892 

11.200 

J/2 

.840 

.542 

1.200 

86 

4.00 

3.358 

13.700 

« 

1.050 

.736 

1.660 

4 

4.50 

3.818 

16.500 

1 

1.315 

.951 

2.360 

5 

5.563 

4.813 

22.800 

1'4 

1.660 

1.272 

3.300 

6 

6.625 

5.750 

32.00 

l'/2 

1.900 

1.494 

4.250 

*  Some  variation  must  be  expected  in  these  weights. 

Stock  lengths  of  Vs  inch  to  2  inches  Standard  Weight  Pipe  average  16  feet  in  length ; 
21/*  inches  to  4  inches,  14  feet  to  16  feet;  5  inches  to  6  inches,  10  feet  to  12  feet. 
Stock  lengths  of  Extra  Heavy  Pipe  run  somewhat  shorter  than  Standard  Weight. 


BRASS  FITTINGS. 
EXTRA  HEAVY— IRON  PIPE  SIZE. 

CAST  IRON  PATTERN. 
For  250  Lbs.  Steam  Working  Pressure. 

TEES,  CROSSES,  AND  Y  BENDS. 


BRASS  FLANGED  FITTINGS 

STANDARD  WEIGHT. 

For  125  Lbs. 


Size ...Inches 


2    |  2>/2  I    3    |  3i/2 


Tees Each  |  .35  1 .40  |  .65  jl.OOi  1.35  |  2.00  \  3.00  |  4.50  |  7.50|ll.00|l6.50|  20.00 


Size Inches 


3M- 


Elbows.  90°.  Faced Each  |25.00|33.75|43.75j  58.75J  68.00|  78.00|  93.00|  123.00 


90°,  Faced  and  Drilled Each  [26.00:35.00  45.00   60.00] _70.00'  80.00]  95.00(125.00 


•Elbows,  45°,  Faced Each  |27.50:37.25:47.75|  63.75]  -73.00!  83.00i  98.00;  133.00 


45°,  Faced  and  Drilled I 


Tees,  Faced 


J28-50J38.50  49.00j _65_.00;_75.00|  85.00  100.00;  135.00 
I37.50J50.75  65] 75|  88.25|  102.00  117.00  137.00  187.00 


Faced  and  Drilled 


.Each  |39.00,52.50;67.50j  90.00|  105.00, 12b7oOj  140.00  190.00 


Crosses,  Faced Each  |50.00|67.50|87.50|  1 17.50|136.00ri56.00|  186~.00~!  246.00 


Tees,  Reducing... Each  |  ..  |  .46   .75  |l.!5J  1.55  |  2.30  |  3.45  |  5.20  |  8.60'l2.65  ~  |  22.00 


Faced  and  Drilled Each  |52.00|70.00:90.00il20.00,140.00:i60.00|  190.00|250.00 


Crosses . 


.Each 


.90|l.30|  1.80  |  2.75  |  4.00  5.25    9.00|l4.00'21.00|  27.00 


Companion  Flanges,  Faced 
Faced  and  Drilled  .. 


.Each 
.  Each 


|10.75jl2.50|15.50|  19.25|  24.25!  26.75J  29.00|  36.50 
|11.00|13.00|16.00|  20.001  25.00|  27.50[  30.00|  37.50 


Crosses,  Red Each  |  ..  |  ..  |l.04|l.50|  2.10  |  3.15  |  4.60  |  6.00  |l0.35|l6.00l24.00|  30.00 


Y  Bends Each 


..  |l.30|l.35|  2.25  |  2.90  |  4.25  |  6.50  |  9.60[l3.25!22.50|  30.00 


Finished  Fittings  at  double  above  lists. 

ELBOWS. 


Dimensions  same  as  Standard  Weight  Cast  Iron  Fittings. 
Reducing  sizes  to  order  at  special  prices. 

EXTRA  HEAVY. 

For  250  Lbs.  Steam  Working  Pressure. 


Size ... Inches 


1    \  IVt     1%  I    2      2V2  |    3      3'/2 


Elbows Each  |  .25  |  .28  |  .36  |  .70  |  1.00  1 1.50  [  2.00  |  3.00  |  5.50  I  8.50J12.501 16.00 


Size ...  Inches 


3»/2 


Elbows,  90°,  Faced Each  |25.00|33.75|43.75|  58.75|  68.00|  78.00|  93.00;  123.0C 


Elbows,  Red Each  |  —  |  .32  |  .42  |  .80  1 1.15  1 1.72  1 2.30  |  3.45  |  6.30  |  9.75|l4.50|  18.50 


90°,  Faced  and  Drilled  ....Each  |26.00|35.00i45.00[  60.00|  70.00|  80.00|  96.00|125.0C 
Elbows,  45°,  Faced Each  [27.50|37.25|47.75|  63.75|  73.00|  83.00|  98.00|133.0( 


Elbows,  R.  and  L.  Each  |  ..  |  .32  |  .42 1 .80  1 1.15  1 1.72  |  2.30  |  3.45  |  6.30  j  9.75|  .. 


Elbows,  45° Each  |  .35  |  .40  |  .43  |  .84  1 1.20  1 1.80  |  2.40  |  3.60  |  6.60  llO.20J15.50l  20.00 


45°.  Faced  and  Drilled -'...Each  |28.50|38.50i49.00|  65.00|  75.00|  85.00[100.00135.(X 


Tees,  Faced . 


.Each  |37.50|50.75!65.75|  88.25il02.00|117.00|137.00|187.(X 


Finished  Fittings  at  double  above  lists. 


Faced  and  Drilled Each  |39.00[52.50!67.50|  90.00|  105.00[  120.00|  140.00|  190.0( 


Crosses,  Faced Each 


Faced  and  Drilled  ...      ...Each 


J50.00|67.50;87.50|117.50!136.0QI156.00|186.00|246.0( 
|52.00[70.00|90.00|120.00|T40.00|i60.00il90.00|250.0( 


Companion  Flanges,  Faced.. .Each  |10.75J12.50|15.50|  19.25|  24.25[  26.75|  29.00J  36.5( 


Faced  and  Drilled ..Each  |11.00|13.00|16.00|  20.00   25.00   27.50J  30.00]  37.5( 


Dimensions  same  as  Extra  Heavy  Cast  Iron  Fittings, 
Reducing  sizes  to  order  at  special  prices. 

Discount  on  all  brass  fittings  flanged  or  screwed,  65  per  cent. 


NOTES  ON  POWER  PLANT  DESIGN 


155 


In 


figuring  the 
90°  or  less 


cost  of  a  bent  pipe,  add  to  the  net  cost  of  the  pipe  and  flanger  the  following  for  each  bend  of 

For  pipe  size  6"        7"        8"        9"        10"        12" 

add  per  bend  $8         $9       $12       $13        $16         $26 


156 


NOTES  ON  POWER  PLANT  DESIGN 
CAST  IRON  PIPE 


Cast  iron  pipe  may  be  used  to  convey  cooling  water  to  the  power  house.  This  pipe  comes 
in  lengths  of  about  twelve  feet  and  has  a  bell  on  one  end  and  a  spigot  on  the  other.  The  joint  be- 
tween the  bell  and  spigot  is  made  by  pouring  in  melted  lead  and  then  calking  with  a  blunt  chisel. 

A  table  giving  the  weights  of  cast  iron  pipe  is  convenient  in  figuring  costs  which  are  taken 
at  a  certain  rate  per  ton,  the  price  depending  upon  the  price  of  pig  iron.  The  price  is  between 

and  $25  a  ton. 

DIMENSIONS   OF  CAST  IRON  PIPE 

Standard  adopted  by  American  Water  Works  Association. 

The  weight  per  length  refers  to  length  of  12  feet  and  includes  allowance  for  bell  and  spigot. 


Nominal 

inside 

dia. 

8 
10 
12 
14 
16 
18 
20 
24 
30 
36 


Class  A 

,  100  ft.  Head 

Thick- 

Weight Lbs. 

ness 

Ft.         Length 

In. 

.46 

42.9          515 

.50 

57.1          685 

.54 

72.5         870 

.57 

89.6        1075 

.60 

108.3        1300 

.64 

129.2        1550 

.67 

150.0        1800 

.76 

204.2        2450 

.88 

192.7        3500 

.99 

391.7        4700 

Class  B,  200  ft.  Head 

Thick- 

Weight Lbs. 

ness 

Ft. 

Length 

In. 

.51 

47.5 

570 

.57 

63.8 

765 

.62 

82.1 

985 

.66 

102.5 

1230 

.70 

125.0 

1500 

.75 

150.0 

1800 

.80 

175.0 

2100 

.89 

233.3 

2800 

1.03 

333.3 

4000 

1.15 

454.2 

5450 

Class  C 

,  300  ft.  Head 

Thick- 

Weight Lbs. 

ness 

Ft.         Length 

In. 

.56 

52.1          625 

.62 

70.8         850 

.68 

91.7        1100 

.74 

116.7        1400 

.80 

143.8        1725 

.87 

175.0        2100 

.92 

208.2        2500 

1.04 

279.2        3350 

1.20 

400.0        4800 

1.36 

545.8        6550 

NOTES  ON  POWER  PLANT  DESIGN 


157 


PIPE  COVERING 

The  heat  radiated  from  a  bare  pipe  is  about  3  B.  T.  U.  per  hour  per  square  foot  of  pipe  sur- 
face per  degree  difference  in  temperature  between  the  steam  inside  the  pipe  and  the  air  in  the  room. 

The  saving  made  by  coverings  of  different  thickness  is  shown  by  the  figures  below  which  apply 
to  a  5"  pipe: 


B.  T.  U.  loss  per  hour  per  square  foot 

of  surface  of  5"  pipe  per  degree 

diff.  in  temperature    .... 


Bare  Pipe 

No 
Covering 


3.00 


Covering     Covering     Covering     Covering 
Thick          Thick          Thick          Thick 


.67 


.43 


.37 


.33 


The  B.  T.  U.  loss  per  square  foot  of  pipe  surface  per  hour  per  degree  difference  in  temperature 
gradually  increases  for  the  covered  pipes  as  the  diameter  of  the  pipe  decreases,  the  values  for  a 
2"  pipe  being  about  20  per  cent  greater  than  the  values  given  above.  For  sizes  over  5"  diameter 
the  values  gradually  decrease  until  at  10"  diameter,  the  figures  are  10  per  cent  lower  than  those 
given. 

The  efficiency  of  a  covering,  or  the  percentage  of  heat  saved,  varies  slightly  with  different  cov- 
erings of  the  same  thickness,  in  general,  however,  a  covering  3"  thick  may  be  assumed  to  have 
an  efficiency  of  88  per  cent  and  one,  1J4"  thick,  85  per  cent. 

The  saving  per  year  due  to  covering  an  8"  header  200  feet  long  supplied  with  steam  at  170 
Ibs.  absolute  superheated  100°  may  be  figured  thus. 

For  high  pressure  steam,  100  to  150  Ibs.,  the  Double  Layer  Double  Standard  Thickness  sectional 
covering  should  be  used.  This  covering  should  be  applied  by  the  broken  joint  method,  each  set 
of  sections  being  thoroughly  wired  in  place.  Outside  of  the  sections  %"  of  plastic  should  be  added 
and  the  whole  covered  with  8  oz.  canvas  sewed  on. 

The  fittings  should  be  covered  with  blocks  and  plastic  or  with  all  plastic  of  a  thickness  to 
correspond  with  the  covering  on  the  pipe. 

The  flanges  should  be  covered  with  removable  flange  covering  made  up  of  blocks  and  plastic, 
1"  thick  on  special  netting,  and  covered  with  canvas  to  match  the  pipe  covering. 

Exhaust  piping,  feed  piping,  drips,  etc.,  should  be  covered  with  Standard  Sectional  Covering 
and  with  regular  canvas  jacket. 

For  standard  thickness  of  covering  apply  45  per  cent  discount  to  list  given.  For  fittings  apply 
45  per  cent.  Note  that  the  cost  of  covering,  the  flanges  on  an  elbow  or  tee  is  not  included  in  the 
cost  as  given  for  elbow  or  tee  and  is  to  be  added. 

For  superheated  steam  lines  the  3"  thickness  is  advisable.  Figure  a  discount  on  3  thickness 
of  35  per  cent.  This  makes  the  price  of  the  3"  thickness  per  lineal  foot  all  installed  with  canvas 
jacket: 

4"  nine  $2.05  for    8"  pipe 

5"    "  2.37  "    10"    " 

6"    "  2.67  "    12" 

7."     " 

For  fittings  covered  with  3"  thickness  use  regular  fitting  prices  as  per  list  for  Standard  Thick- 
ness and  add  10  per  cent. 

Removable  flange  covers  for  this  thickness  of  covering  would  be  2'  thick  and  the  cost  of  thes 
covers  is  not  included  in  the  cost  of  elbows  and  tees  as  given  in  the  price  list. 

The  price  of  these  flange  covers  installed  is  10  per  cent  above  the  figures  given  in  the  right  1 

Boiler  drums  should  be  covered  with  blocks  2"  thick  and  K"  of  plastic  added.  Such  covering 
costs  35  cents  per  square  foot  area  of  the  external  surface  of  the  covering. 


&1.43  for 
1.63  " 
1.76  " 
1.89  " 


158 


NOTES  ON  POWER  PLANT  DESIGN 


For  smoke  flues,  flues  leading  to  economizers,  etc.,  blocks  1"  thick  should  be  wired  on  and  cov- 
ered with  3^"  of  plastic.     This  costs  25  cents  a  square  foot. 

The  outside  diameter  of  8"  pipe  is  8.625",  the  circumference  in  feet  is  2.258. 

The  totahsurface  of  200  ft.  of  pipe  is  451.6  sq.  ft.  and  the  B.  T.  U.  loss  per  year  is  365  X  24 
X  451.6  x  3  X  (468.5  -  68.5)  =  4,747,200,000,  assuming  room  to  be  68.5°  F. 

If  10,000  B.  T.  U.  are  utilized  by  the  boiler  per  Ib.  of  coal  burned,  the  coal  required  to  supply 
this  loss  would  be  474,200  Ibs.  or  237.1  tons.     At  $4.50  per  ton  this  amounts  to  $1067. 

If  a  covering  3"  thick  is  used,  an  efficiency  of  88  per  cent  may  be  assumed.     The  saving  due 
to  the  covering  becomes  .88  x  1067  =  $939  per  year. 

The  first  cost  of  the  covering  would  be  for  the  200  feet  of  pipe  200  x  $2.05  =  $410 

10  pairs  of  flanges  10  x  $2.53  =      25.30 


$435.30 

The  covering  would  more  than  pay  for  itself  in  six  months. 

The  cost  of  a  covering  may  be  figured  from  the  price  list,  noting  the  discount  given  on  the 
different  items. 


PRICE  LIST  OF  85%  MAGNESIA  AND  ALL  OTHER  SECTIONAL  COVERINGS 


Price  per 

Inside 

Standard 

Line  al 

Diameter 

Thickness 

Foot  Can- 

of 

of 

vas  Jacketed 

.    Pipe 

Covering 

K" 

%" 

$.22 

%" 

¥*',', 

.24 

l" 

.27 

1/4" 

X" 

.30 

IK" 

X" 

.33 

2" 

u;; 

.36 

2K" 

.40 

3" 

i*;; 

.45 

3K" 

.50 

4" 

fX" 

.60 

4K" 

IK" 

.65 

5' 

IK" 

.70 

6' 

iy8" 

.80 

7' 

IX" 

1.00 

8' 

IX" 

1.10 

9' 

IX" 

1.20 

10' 

ix*;t 

1.30 

12' 

* 

1.85 

14' 

IK" 

2.10 

16' 

IX" 

2.35 

18' 

2.60 

20' 

iK" 

2.85 

24' 

IK" 

3.30 

30' 

IK" 

4.00 

Price  per 

Lineal 

Thickness 

Foot  Can- 

of 

vas  Jacketed 

Covering 

IK" 

$.46 

IK" 

.49 

IK" 

.52 

IK" 

.56 

IK" 

.60 

IK" 

.64 

IK" 

.70 

IK" 

.76 

IK" 

.82 

IK" 

.88 

IK" 

.94 

IK" 

1.00 

IK" 

1*10 

IK" 

1.20 

IK" 

1.35 

IK" 

1.50 

IK" 

1.65 

IK" 

1.85 

IK;; 

2.10 

2.35 

IK" 

2.60 

IK" 
IK" 
IK" 


2.85 
3.30 
4.00 


Thickness 

of 
Covering 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 

2' 


Price  per 

Lineal 
Foot  Can- 
vas Jacketed 

$.75  -. 

.80 

.85 

.90 

.'95 
1.00 
1.05 


IS 

25 

:;:> 
45 

55 


1.70 


1.85 

2.00 

2 . 20 

2.40 

2.70 

00 

30 


00 
50 


5.50 


*A11  coverings  above  10  in.  furnished  in  segment  form;  jackets  not  included  in  the  prices. 


NOTES  ON  POWER  PLANT  DESIGN 


159 


PRICE  LIST  OF  85%  MAGNESIA  AND  ALL  OTHER  SECTIONAL  COVERINGS  —  Cont. 


Block  List 

Double           Price  per 

Price  per 

Double 

Price  per 

Layer 

Lineal 

Double            Lineal 

Layer. 

Lineal 

Double 

Double           Foot  Can- 

layer.     To-     Foot  Can- 

Double 

Foot  Can- 

layer. To 

Standard         vas  Jack- 

tal  Thick-       vas  Jack- 

Standard 

vas  Jack- 

tal Thick- 

Thickness           eted 

ness  3  in.            eted 

Thickness 

eted 

ness  8  in. 

IK' 

$.65 

3' 

$1.20 

H" 

$.27 

2y$" 

w, 

.70 

3' 

1.35 

%" 

.27 

2J4" 

.75 

3' 

1.40 

%" 

.30 

2%" 

\y± 

.80 

3' 

1.45 

1" 

.30 

2^;; 

i/4' 

.85 

3' 

1.55 

iy8" 

.34 

2i.' 

.90 

3' 

1.65 

1/4" 

.38 

224" 

2$; 

1.00 

3' 

1.75 

I/Is" 

.42 

2%" 

1.10 

3' 

1.90 

iy2" 

.45 

3" 

2JV 

1.20 

3' 

2.05 

i%" 

.49 

3/4" 

1.40 

3' 

2.20 

1/4" 

.53 

3y%" 

2^4' 

1.50 

3' 

2.35 

i%" 

.57 

4 

2/4' 

1.60 

3' 

2.50 

2" 

.60 

2%' 

1.80 

3' 

2.70 

2y2r 

2.25 

3' 

2.90 

2y2r 

2.50 

3' 

3.15 

2y2' 

2.70 

3' 

3.40 

2y2r 

2.90 

3' 

3.65 

3' 

4.10 

3' 

4.10 

X 

3' 

4.60 

3' 

4.60 

3' 

5.10 

3' 

5.10 

3' 

5.60 

3' 

5.60 

3' 

6.00 

3' 

6.00 

3' 

7.00 

3' 

7.00 

3' 

8.40 

3'                 8.40 

Sizes 

of 

G. 

Flange 

Fittings 

Elbows              Tees 

Crosses 

Valves 

Covers 

i^" 

$.30               $.36 

$.48 

$.54 

$.50 

H" 

.30                  .36 

.48 

.54 

.50 

i" 

.30                  .36 

.48 

.54 

.50 

1/4" 

.30                 .36 

.48 

.54 

.50 

1/^2" 

.30                 .36 

.48 

.54 

.50 

2" 

.36                  .42 

.54 

.60 

.60 

2y>" 

.42                  .48 

.60 

.78 

.70 

3" 

.48                  .54 

.70 

.96 

.80 

sy2" 

.54                 .60 

.80 

1.20 

.90 

4" 

.60                 .75 

.95 

1.50 

1.00 

4H" 

.72                 .90 

1.10 

1.85 

1.30 

5" 

.90               1.20 

1.50 

2.25 

1.60 

6" 

1.30               1.60 

2.00 

2.80 

1.90 

7" 

1.80               2.20 

2.80 

3.60 

2.20 

8" 

2.40               3.00 

3.60 

4.40 

2.50 

9" 

3.00               3.80 

4.40 

5.30 

2.90 

10" 

3.60               4.60 

5.20 

6.20 

3.30 

Price  per 

Lineal 
Foot  Can- 
vas Jack- 
eted 
$.64 

.68 

.72 

.75 

.79 

.83 

.87 

.90 

.98 
1.05 
1.20 


160  NOTES  ON  POWER  PLANT  DESIGN 


SPECIFICATIONS 

The  specifications  for  a  Condensing  Equipment  for  a  1500  K.  W.  Low  Pressure  Steam  Turbine; 
for  Automatic  Pump  and  Receiver;  for  Direct  Acting  Boiler  Feed  Pumps  and  for  Turbine  Driven 
Centrifugal  Boiler  Feed  Pumps  were  furnished  by  Mr.  B.  R.  T.  Collins  '88. 


SPECIFICATIONS 

FOR 

CONDENSING  EQUIPMENT 
Including 

SURFACE  CONDENSER,  HOT  WELL  PUMP,  DRY  VACUUM  PUMP 

1.  NUMBER  WANTED.     One. 

2.  TYPE.     Surface  condenser  with  separate  wet  and  dry  air  pumps. 

3.  CAPACITY. 

Amount  of  steam  to  be  condensed,  000  Ibs.  per  hour. 
Temperature  of  injection  water,  70°  Fahrenheit. 

Absolute  pressure  in  condenser,  2  inches  of  mercury  or  28  inches  vacuum  referred  to  a 
30-inch  barometer. 

4.  CHARACTER  OF  CIRCULATING  WATER. 

Fresh  river  water. 

5.  SOURCE  OF  CIRCULATING  WATER. 

From  factory  water  supply  system.  Any  quantity  up  to  000  gallons  per  min.  at  any 
pressure  required. 

6.  RELATIVE  LOCATION  OF  CONDENSING  EQUIPMENT  AND  TURBINE. 

The  surface  condenser  with  the  dry  air  pump  will  be  located  directly  beneath  the  horizontal 
turbine  to  which  it  will  be  connected  and  as  near  to  it  as  practicable.  The  wet  or  hot 
well  pump  can  be  located  as  much  below  this  level  as  required.  The  exhaust  outlet 
of  the  turbine  will  look  down. 

7.  EQUIPMENT  TO  BE  FURNISHED. 

The  equipment  to  be  furnished  includes  surface  condenser,  wet  or  hot  well  pump  and 
dry  air  or  dry  vacuum  pump  required  to  give  the  results  stated  under  "CAPACITY." 

The  hot  well  pump  shall  be  of  the  duplex  direct-acting  steam  driven  type. 

The  dry  vacuum  pump  shall  be  of  the  rotative  steam  driven  type. 

The  condenser  proper,  hot  well  and  dry  vacuum  pumps  are  described  in  detail  under  sep- 
arate specifications  following. 


SPECIFICATIONS  FOR  SURFACE  CONDENSER 

1.  NUMBER  WANTED.     One. 

2.  CONSTRUCTION. 

This  surface  condenser  shall  contain  not  less  than  000  sq.  ft.  of  cooling  surface.  The  shell 
and  heads  are  to  be  furnished  with  openings  for  the  exhaust  steam,  circulating  water 
inlet  and  discharge,  dry  air  and  condensed  steam,  of  sizes  and  locations  approved  by 
the  Engineer. 


NOTES  ON  POWER  PLANT  DESIGN  161 

The  tube  heads  are  to  be  of  rolled  brass. 

The  tubes  are  to  be  seamless  drawn  brass  of  the  following  composition: 

Copper  60% 

Zinc  40% 

Every  tube  is  to  be  inspected  for  faults  on  both  inside  and  outside  and  all  tubes  show- 
ing any  indication  of  imperfection  of  any  kind  are  to  be  rejected. 

The  condenser  is  to  be  tested  under  25  Ibs.  per  sq.  in.  cold  water  pressure  applied  in  both 
steam  and  water  spaces  before  shipment  from  the  factory  and  made  tight. 

The  interior  of  the  shell  is  to  be  carefully  painted  with  two  coats  of  anti-rust  metallic  paint. 
The  whole  exterior  is  to  be  scraped,  filled  and  painted  with  the  best  lead  and  oil  paint 
before  leaving  the  shops. 

All  interior  bolting  in  contact  with  the  circulating  water  is  to  be  pf  composition  unless 
otherwise  specified. 

3.  BOLTS,  ETC. 

Bolts,  nuts  and  screws  shall  be  of  the  United  States  standard. 

4.  FINISH. 

All  castings  shall  be  carefully  dressed  down,  filled  and  painted  with  the  best  quality  of 
paint. 

5.  DRILLING. 

All  flanges  shall  be  faced  and  drilled  in  accordance  with  Manufacturers'  Standard  for  flanges 
and  drilling. 

6.  DESIGN,  MATERIAL  AND  WORKMANSHIP. 

The  design  shall  be  such  as  to  insure  safe,  reliable  and  economical  operation. 

The  material  and  workmanship  shall  be  the  best  of  their  respective  kinds. 

The  contractor  shall  furnish,  without  charge,  F.  O.  B.  cars,  a  duplicate  of  any  part  that 

may  prove  defective  in  material  or  workmanship  within  one  year  after  the  condensing 

equipment  has  been  started. 

7.  DRAWINGS. 

Bidder  shall  submit  in  connection  with  his  proposal  an  outline  drawing  to  scale  and  a 
description  of  the  condenser  he  proposes  to  furnish,  giving  in  detail  the  design,  and 
arrangement  made  for  removal  of  parts  and  for  repairs. 

8.  CONDENSER  DATA. 

The  bidder  shall  furnish  the  following  data  on  each  condenser: 

Number  of  tubes m 

Length  of  tubes ft in. 

Outside  diameter  of  tubes in. 

Thickness  of  tubes    No.  18  B.  W.  G. 

Thickness  of  tube  heads in. 

Cooling  surface    sq.  ft. 

Material  of  tubes    

Area  exhaust  opening 

Size  of  circulating  water  inlet  opening  . .    in. 

Size  of  circulating  water  discharge  opening   in. 

Size  dry  air  opening   in. 

Approximate  finished  weight Ibs. 

Approximate  shipping  weight     Ibs. 


162  NOTES  ON  POWER  PLANT  DESIGN 

SPECIFICATION   FOR  DIRECT  ACTING   HOT  WELL  PUMP 

1.  NUMBER  WANTED.     One. 

2.  TYPE.    Hprizontal  duplex  piston  type. 

3.  KIND  OF  SERVICE. 

Removing  condensed  steam  from  surface  condenser. 

4.  WORKING  STEAM  PRESSURE.     175  Ibs.  per  sq.  in.  gage. 

5.  MINIMUM  STEAM  PRESSURE.     125  Ibs.  per  sq.  in.  gage. 

6.  STEAM  TEMPERATURE.    527.6°  F.  (approx.)  or  150°  superheat. 

7.  BACK  PRESSURE.     17  Ibs.  per  sq.  in.  absolute. 

8.  DISCHARGE  WATER  PRESSURE.    Not  over  15  ft.  head. 

9.  CAPACITY. 

The  pump  shall  be  capable  of  delivering  at  least gallons  of  water  per  minute  under 

the  conditions  of  operation  as  described  in  this  specification. 

10.  WATER  END  FITTINGS. 

Bronze  cylinder  linings,  piston  rods,  pistons,  stuffing  box  glands,  valve  seats,  bolts,  plates 
and  springs.  Hard  rubber  valves  for  212°  F.  water. 

11.  LUBRICATION. 

There  shall  be  furnished  with  the  pump  one  (1)  pint  "Detroit"  lubricator. 

12.  DRILLING. 

All  flanges  shall  be  faced  and  drilled  in  accordance  with  Manufacturers'  Standard  for  flanges 
and  drillings. 

13.  MATERIAL  AND  WORKMANSHIP. 

The  material  and  workmanship  shall  be  the  best  of  their  respective  kinds.  The  Contractor 
shall  furnish  without  charge  F.  O.  B.,  a  duplicate  of  any  part  that  may  prove  defective 
in  material,  or  workmanship  one  year  after  the  pump  has  been  started. 

14.  DRAWING'S. 

Bidder  shall  submit  in  connection  with  his  proposal,  an  outline  drawing  to  scale  and  a  de- 
scription of  the  pump  he  proposes  to  furnish,  giving  all  necessary  details. 

15.  PUMP  DATA. 

Bidder  shall  furnish  the  following  data  on  the  pump: 

Diameter  steam  cylinder ins. 

Diameter  water  cylinder    ins. 

Length  of  stroke   ins. 

Diameter  steam  inlet   ins. 

Diameter  exhaust  outlet    ins. 

Diameter  suction ins. 

Diameter  discharge ins. 

Approximate  finished  weight Ibs. 

Approximate  shipping  weight     Ibs. 

SPECIFICATION   FOR  ROTATIVE  DRY  VACUUM  PUMP 

1.  NUMBER  WANTED.    One. 

2.  TYPE. 

Horizontal,  crank  and  fly  wheel  rotative  dry  vacuum  pump. 

3.  KIND  OF  SERVICE. 

Removing  non-condensible  vapors  from  condenser. 

4.  SPEED. 

Not  over  150  R.  P.  M.     Piston  speed  not  over  300  feet  per  minute. 

5.  WORKING  STEAM  PRESSURE.     175  Ibs.  per  sq.  in.  gage. 

6.  MINIMUM  STEAM  PRESSURE.     125  Ibs.  per  sq.  in.  gage. 

7.  STEAM  TEMPERATURE.     527.6°  F.  (approx.)  or  150°  superheat. 


NOTES  ON  POWER  PLANT  DESIGN  163 

8.  BACK  PRESSURE.     17  Ibs.  per  sq.  inch  absolute. 

9.  CAPACITY. 

The  capacity  of  this  air  pump  shall  be  at  least  35  times  the  volume  of  the  condensed  steam. 

10.  CYLINDERS. 

The  cylinders  shall  be  of  close-grained  cast  iron. 

The  air  cylinder  shall  be  strong  enough  to  withstand  a  normal  working  pressure  of  50  Ibs. 
per  sq.  in.  and  the  steam  cylinder  shall  be  strong  enough  to  withstand  a  steam  pressure 
of  200  Ibs.  per  sq.  in.  after  being  rebored  %"  in  diameter  without  causing  the  tensile 
strength  in  the  metal  to  exceed  2500  Ibs.  per  sq.  in.  The  steam  cylinder  shall  be  lagged 
with  85%  carbonate  of  magnesia  held  on  with  Russia  iron  covering.  Provision  shall 
be  made  on  both  the  steam  and  air  cylinders  for  attaching  indicators.  All  cylinders 
shall  be  provided  with  drip  cocks.  The  steam  and  air  ports  shall  be  of  ample  size  to 
allow  easy  and  quick  action  of  the  steam  and  air.  All  parts  shall  be  so  arranged  as 
to  be  readily  accessible. 

11.  STEAM  VALVES  AND  VALVE  MOTION. 

Throttle  valve  will  be  furnished  by  the  purchaser. 

The  steam  valve  shall  be  of  the  balanced  type  with  provision  for  taking  up  wear. 

12.  AIR  VALVES. 

The  air  valves  shall  be  of  a  suitable  type  for  obtaining  the  greatest  vacuum  under  the 
conditions  herein  specified. 

13.  LUBRICATION. 

Ample  lubrication  shall  be  provided  for  all  parts  subject  to  wear.  There  shall  be  fur- 
nished with  pump  one  (1)  nickle  plated,  2  qt.,  two  feed  Richardson  sight  feed  lubri- 
cator with  divided  reservoir  for  supplying  two  different  kinds  of  oil,  one  for  the  steam 
cylinder  and  the  other  for  the  air  cylinder. 

14.  WRENCHES. 

One  full  set  of  wrenches  shall  be  furnished  with  the  pump. 

15.  BOLTS,  ETC. 

Bolts,  nuts  and  screws  shall  be  of  the  United  States  standard. 

16.  FINISH. 

The  working  parts  of  the  pump  shall  be  highly  finished,  all  exposed  metal  parts  usually 
polished,  such  as  cylinder  cover  and  the  faces  of  flywheels,  shall  be  smooth  turned,  and 
together  with  all  castings  carefully  filled  and  painted  \\ith  the  best  quality  of  paint. 

17.  DRILLING. 

All  flanges  shall  be  faced  and  drilled  in  accordance  with  Manufacturers'  Standard. 

18.  DESIGN,  MATERIAL  AND  WORKMANSHIP. 

The  design  shall  provide  ample  bearing  surfaces,  abundant  lubrication  and  strong  rugged 
parts  and  shall  insure  safe,  reliable  and  economical  operation. 

The  material  and  workmanship  shall  be  the  best  of  their  respective  kinds.  The  contractor 
shall  furnish  without  charge  f .  o.  b.  a  duplicate  of  any  part  that  may  prove  defective 
in  material  or  workmanship  within  one  year  after  the  pump  has  been  started. 

19.  DRAWINGS. 

Bidder  shall  submit  in  connection  with  his  proposal,  an  outline  drawing  to  scale  and  n 
description  of  the  pump  he  proposes  to  furnish,  giving  in  detail  the  design  of  pistons, 
plungers,  valves,  and  arrangement  made  for  removal  of  parts  and  for  repairs. 

20.  PUMP  DATA. 

Bidder  shall  furnish  the  following  data  on  the  pump : 
DIMENSIONS: 

Diameter  steam  cylinder ins. 

Diameter  air  cylinder ins. 

Length  of  stroke   ins. 


164  NOTES  ON  POWER  PLANT  DESIGN 

FLOOR  SPACE: 

Length ft ins. 

Width    ft , . .  .ins. 

Height ft ins. 

PIPE  OPENING: 

Steam    ins.     Suction ins. 

Exhaust ins.     Discharge    ins. 

STEAM  END: 

Type  of  steam  valve 

Area  admission  ports    sq.  ins. 

Area  exhaust  ports   sq.  ins. 

AIR  END: 

Type  of  air  valve 

Area  admission  ports    sq.  ins. 

Area  exhaust  ports   sq.  ins. 

BEARINGS: 

Diameter  main  bearings ins. 

Length  main  bearings ins. 

Diameter  crank  pin ins. 

Length  crank  pin ins. 

Diameter  wrist-pin ins. 

Length  wrist-pin ins. 

Diameter  of  shaft   ins. 

Dimensions  of  cross-head  shoes    ins. 

GOVERNOR: 

Type  of  governor 

FLYWHEEL: 

Diameter ft ins. 

Width  of  face ins. 

APPROXIMATE  WEIGHTS: 

Finished  weight Ibs. 

Shipping  weight Ibs. 


SPECIFICATION  FOR  1500  K.  W.  MAXIMUM  RATED  HORIZONTAL  LOW  PRESSURE 

STEAM  TURBINE 

STEAM  END 

1.  NUMBER  WANTED.    One. 

2.  TYPE.     Horizontal  low  pressure  condensing. 

3.  KIND  OF  SERVICE.     Direct  connected  to  generator  supplying  current  for  factory  motors 

and  motor-generators  or  rotaries. 

4.  SPEED.    Revolutions  per  minute. 

5.  STEAM  PRESSURE  AT  THROTTLE.     Fifteen  pounds  absolute.     Alternate  proposition  on  turbine 

suitable  to  use  both  fifteen  pounds  absolute  and  175  pounds  per  sq.  in.  gage. 

6.  STEAM  TEMPERATURE  AT  THROTTLE.    Temperature  due  to  pressure  given  above.     No  super- 

heat. 

7.  BACK  PRESSURE.     2"  of  mercury  absolute. 

8.  REGULATION.     The  speed  of  the  turbine  shall  not  vary  more  than  2J^%  above  or  below 

the  normal  speed  at  any  load  less  than  500  K.  W.  Maximum  speed  variation  where 
full  load  is  thrown  on  or  off  instantaneously  will  not  exceed %.  The  con- 
tractor shall  furnish  as  part  of  the  turbine  an  electrical  synchronizing  device  for  vary- 
ing the  speed  of  the  turbine  from  the  switchboard. 


NOTES  ON  POWER  PLANT  DESIGN  165 

9.     CAPACITY.     When  operating  condensing  under  the  condition  herein  stated  the  turbine  shall 
furnish  power  to  generate, — 

1500  K.  W.  continuously; 
2000  K.  W.  momentarily. 

10.  THROTTLE  VALVE.    The  throttle  valve  shall  be  of  the  Schutte  and  Koerting  make,  actuated 

at  a  speed  of  10%  above  normal  by  a  safety  governor. 

11.  BOLTS,  NUTS,  ETC.     Bolts,  nuts  and  screws  shall  be  of  the  United  States  Standard. 

12.  FINISH.     The  turbine  as  a  whole  shall  be  highly  polished,  all  exposed  metal  parts  polished 

and  castings  carefully  dressed  down,  filled  and  painted  with  the  best  quality  of  paint. 

13.  DRILLING.     All  flanges  shall  be  faced  and  drilled  in  accordance  with  Manufacturers'  Standard 

for  flanges  and  drilling. 

14.  STEAM  CONSUMPTION.    The  turbine  shall  consume  not  more  than  the  amounts  of  steam 

given  below  when  developing  the  corresponding  kilowatts,  running  at  a  speed  of 

revolutions  per  minute,  with  a  steam  pressure  of  fifteen  pounds  absolute  per  sq.  in.  and 
exhausting  against  a  back  pressure  of  2  inches  of  mercury  absolute.  The  steam  pressure 
shall  be  the  averaged  measured  just  outside  the  throttle  valve,  and  the  back  pressure 
shall  be  measured  in  the  exhaust  pipe  near  the  turbine. 

Steam  Consumption  Pounds  per  K.  W.  hour 

K.  W Ibs.  per  K.  W.  H. 

375 '.  .Ibs.  per  K.  W.  H. 

750 Ibs.  per  K.  W.  H. 

1125    Ibs.  per  K.  W.  H. 

1500    Ibs.  per  K.  W.  H. 

15.  ERECTION.    The  contractor  shall  provide  for  the  superintendence  of  erection  of  the  turbine, 

all  common  labor  to  be  provided  by  the  purchaser.  The  contractor  agrees  to  have  the 
turbine  and  generator  erected  ready  for  operation  within  15  days  after  their  arrival  at 
destination  provided  no  delays  are  caused  by  the  purchaser. 

16.  DESIGN,  MATERIAL  AND  WORKMANSHIP.     The  design  shall  provide  ample  bearing  surfaces, 

abundant  lubrication  and  strong  rugged  parts,  and  shall  insure  safe,  reliable  and  econo- 
mical operation,  and  without  undue  heating  or  vibration.  The  material  and  workman- 
ship shall  be  the  best  of  their  respective  kinds.  The  contractor  shall  furnish,  without 
charge,  f.  o.  b.,  a  duplicate  of  any  part  that  may  prove  defective  in  material  or  work- 
manship within  one  year  after  the  turbine  has  been  started. 

17.  DRAWINGS.     Bidder  shall  submit  in  connection  with  his  proposal  an  outline  drawing  to  scale 

and  a  description  of  the  turbine  he  proposes  to  furnish,  giving  in  detail  the  arrange- 
ments made  for  the  removal  of  parts  for  repairs. 

18.  TURBINE  DATA.    Bidder  shall  furnish  the  following  data  on  the  turbine: 

DIMENSIONS  : 

Length 

Width   

Height 

PIPING: 

Steam    * 

Exhaust 

WEIGHT: 

Weights  of  heaviest  part   

Weight  of  heaviest  part  to  be  moved  when  mak- 
ing ordinary  repairs  

Shipping  weight 

Finished  weight 


166  NOTES  ON  POWER  PLANT  DESIGN 

GENERATOR  END 

1.  NUMBER  WANTED.    One. 

2.-  TYPE.    Revolving  field. 

3.  KIND  OF  SERVICE.     Supplying  current  for  factory  motors  and  motor-generators  or  rotaries. 

4.  SPEED.     Revolutions  per  minute 

5.  NUMBER  OF  POLES 

6.  FREQUENCY.     60  cycles  per  second. 

7.  PHASE.     Three  phase. 

8.  VOLTAGE.    480  at  no  load. 

480  at  full  load,  80%  power  factor. 

9.  REGULATION.    The  regulation  of  generator  when  operating  at  100%  load  and  80%  power 

factor  shall  not  exceed %.     By   "regulation"   is  meant  the  rise  in 

potential  of  generator  when  specified  load  at  specified  power  factor  is  thrown  off. 

10.  CAPACITY.    The  generator  shall  develop: 

1500  K.  W.  continuously. 
2000  K.  W.  momentarily. 

Generator  shall  be  capable  of  developing  K.  W.  as  above,  at  voltage  specified  above  and 
at  any  power  factor  not  less  than  80%. 

11.  AMPERES.     Full  load  current amperes  per  phase. 

12.  TEMPERATURE  RISE.     Shall  not  exceed  the  following: 

When  generating  continuously  at  1500  K.  W. 

480  volts. 

80%  Power  Factor. 

Field  and  armature  by  thermometer  50  deg.  C. 

Collector  rings  and  brushes  by  thermometer      50  deg.  C. 
Bearings  and  other  parts  by  thermometer          50  deg.  C. 

13.  STYLE  OF  FIELD  WINDING.     Separately  excited. 

14.  EXCITATION.     Excitation  of  separately  excited  fields  shall  be  by  direct  current  at  125  V.   It 

shall  not  be  necessary  to  raise  excitation  above  125  V.  in  order  to  maintain  voltage  spec- 
ified above  on  the  generator  with  1500  K.  W.  load  and  80%  power  factor. 

15.  RHEOSTAT.     A  hand  operated  rheostat  shall  be  furnished  in  field  circuit  to  control  the  voltage. 

16.  FIELD  DISCHARGE  RESISTANCE.     A  suitable  field  discharge  resistance  shall  be  furnished. 

17.  RHEOSTAT  MECHANISM.     The  generator  field  rheostat  shall  be  furnished- with  hand  wheel 

and  chain  operating  mechanism  suitable  for  mounting  on  switchboard  panel. 

18.  PARALLEL  OPERATION.     The  generator  shall  be  designed  so  that  it  may  be  operated  in  parallel 

with  other  machines  of  similar  type,  of  the  same  or  different  size,  or  inductive  or  non- 
inductive  loads  without  seriously  disturbing  the  regulation  of  any  of  the  machines,  or 
affecting  the  lights  on  the  line. 

19.  INSULATION  TEST.     The  ohmic  resistance  and  dielectric  strength  of  the  insulation  shall  meet 

the  requirements  of  the  latest  report  of  the  Committee  on  Standardization  of  the  Amer- 
ican Institute  of  Electrical  Engineers. 

20.  GENERATOR  DATA.     Bidder  shall  furnish  the  following  data  on  generator: 

Maximum  voltage  that  can  be  obtained  from  generator  at  100%  load  and  80%  power 

factor  will  be volts. 

The  commercial  efficiency  of  the  generator  will  be  as  follows: 

%  at  %  load. 

%  at  ^  load. 

%  at  %  load. 

%  at  full  load. 

Exciting  current  at  full  load  and  80%  power  factor  will  be amperes  at 

125  volts.     Maximum  current  on  short  circuit  will  be .amperes  at  unity 

power  factor.    Shipping  weights  will  be  as  follows: 

Rotor pounds. 

Generator  complete pounds. 

Heaviest  piece •. . .  pounds. 


NOTES  ON  POWER  PLANT  DESIGN  167 

SPECIFICATION  FOR  DIRECT  ACTING  BOILER  FEED  PUMPS 

1.  NUMBER.     Two. 

2.  TYPE.     Horizontal  duplex  outside  packed  plunger. 

3.  SERVICE.     Boiler  feed. 

4.  WORKING  STEAM  PRESSURE.     175  Ibs.  per  sq.  inch  gage. 

5.  WORKING  EXHAUST  PRESSURE.     17  Ibs.  absolute. 

6.  WORKING  DISCHARGE  WATER  PRESSURE.     250  Ibs.  per  sq.  inch. 

7.  WORKING  SUCTION  HEAD.     8  ft.  above  floor  on  which  pump  stands. 

8.  TEMPERATURE  OF  WATER.     212  deg.  F. 

9.  CAPACITY.     Normal  capacity  250  gallons  per  minute  for  each  pump.    Maximum  capacity 

500  gallons  per  minute  for  each  pump. 

10.  WATER  END  FITTINGS.     Hard,  close-grained  cast  iron  plungers,  composition  covered,  bronze 

stuffing  box  glands,  valve  seats,  and  valves  of  the  pot  valve  type. 

11.  AIR  CHAMBERS  of  proper  capacity  and  length  to  be  furnished  for  both  suction  and  discharge 

connections. 

12.  PROPOSAL.     Make  proposal  f.  o.  b..  .stating  price;  time  before  shipment;  shipping  weight; 

and  enclose  print  showing  general  dimensions  and  sizes  of  all  connections. 

SPECIFICATION  FOR  TURBINE  DRIVEN  CENTRIFUGAL  BOILER. FEED  PUMPS 

1.  TYPE.     Multistage  Centrifugal  Pumps,  direct  connected  to  Steam  Turbines,  on  common 

bed  plate  with  flexible  shaft  coupling. 

2.  NUMBER.     Two. 

3.  SERVICE.     Boiler  Feed. 

4.  MAXIMUM  CAPACITY.     500  gallons  per  minute  for  each  pump. 

Capacity  for  most  economical  steam  consumption, —  250  gallons  per  minute  for  each 
pump. 

5.  WORKING  DISCHARGE  WATER  PRESSURE.     250  pounds  per  square  inch. 

6.  WORKING  SUCTION  HEAD  ABOVE  CENTER  OP  PUMP  SHAFT.     8  ft.  of  water. 

7.  WORKING  STEAM  PRESSURE.     175  Ibs.  per  square  inch,  gage. 

8.  WORKING  EXHAUST  PRESSURE.     17  Ibs.  absolute. 

9.  MAKE  PROPOSAL  f.o.  b..  .stating  price;  time  before  shipment;  shipping  weight;  print  showing 

general  dimensions  and  sizes  of  all  connections;  guaranteed  steam  consumption  of  tur- 
bine at  maximum  rating  of  500  gallons  per  minute,  also  at  250  gallons  per  minute  in 
pounds  per  H.  P.  per  hour  and  efficiency  of  pump  at  each  of  above  capacities. 

SPECIFICATION  FOR  AUTOMATIC  PUMPS  AND  RECEIVERS 

1.  NUMBER.     Five. 

2.  TYPE.     Alternate  propositions  on  (1st)  single  cylinder  direct  acting  piston  type  steam  pump 

with  receiver  and  automatic  arrangement  for  starting  and  stopping  pump  and  (2nd) 
horizontal  duplex  piston  type  with  receiver  and  automatic  arrangement  for  starting  and 
stopping  pump. 

3.  SERVICE.     Returning  hot  water  drips  from  trap  discharges,  heating  and  curing  systems,  etc., 

to  open  feed  water  heater. 

4.  WORKING  STEAM  PRESSURE.    Maximum  100  per  sq.  inch;  minimum  20  per  sq.  inch. 

5.  WORKING  EXHAUST  PRESSURE.     17  absolute. 

6.  WORKING  DISCHARGE  WATER  PRESSURE.     Not  over  40  ft.  head  including  pipe  friction. 

7.  WORKING  SUCTION  HEAD.     Gravity  and  trap  returns  to  receiver. 

8.  TEMPERATURE  OF  WATER.     150  deg.  F.  to  212  deg.  F. 

9.  CAPACITY.     Four  pumps  60  gallons  per  minute  and  the  fifth  pump  100  gallons  per  minute. 


168  NOTES  ON  POWER  PLANT  DESIGN 

10.  WATER  AND  FITTINGS.     Three  60-gallon  and  one  100-gallon  pumps  bronze  cylinder  linings, 

piston  rods,  pistons,  stuffing  box  glands,  valve  seats,  bolts,  plates  and  springs.  Hard 
rubber  valves  for  212  deg.  F.  water.  Water  piston  to  have  metallic  packing  rings  and 
also  to  be  arranged  for  the  use  of  fibrous  packing  if  desired.  One  60-gallon  pump  and 
receiver  to  be  iron  fitted  throughout,  no  bronze  whatever.  (For  use  with  water  contain- 
ing sulphur.) 

11.  PROPOSAL.     Make  proposal  stating  price  for  both  sizes  of  pumps  in  both  single  and  duplex 

types;  also  60-gallon  pump  and  receiver:  iron  fitted  throughout;  time  before  shipment; 
shipping  weights;  prints  showing  general  dimensions  and  sizes  of  all  connections  and 
details  of  float  and  steam  regulating  valve  with  connections  between  them. 

SPECIFICATIONS  FOR  30"  x  60"  x  60"  HORIZONTAL  CROSS-COMPOUND  NON- 
CONDENSING  CORLISS  ENGINE 

1.  NUMBER  WANTED.     One. 

2.  TYPE.     Horizontal  Corliss,  cross-compound,  non-condensing. 

3.  KIND  OF  SERVICE.     Rope  drive  to  factory  line  shafting.     Exhausting  to  low  pressure  steam 

turbine. 

4.  INDICATED  HORSE  POWER: 

At  lowest  steam  consumption 

At  maximum  load 

5.  SPEED.     80  revolutions  per  minute. 

6.  STEAM  PRESSURE  AT  THROTTLE.     175  Ibs.  per  sq.  in.  gauge. 

7.  STEAM  TEMPERATURE  AT  THROTTLE.    377°  F. 

8.  BACK  PRESSURE.     17  Ibs.  per  sq.  in.  absolute. 

9.  POINT  OF  CUT-OFF: 

At  lowest  steam  consumption % 

At  maximum  load % 

10.  REGULATION.    The  speed  of  the  engine  shall  not  vary  more  than  2J^  per  cent  above  or  below 

the  normal  speed  at  any  load  less  than indicated  horse  power. 

11.  CYLINDER  SIZES.     The  dimensions  of  the  cylinder  shall  be  as  follows : 

Diameter    Stroke 

High  pressure  cylinder 30"  60" 

Low  pressure  cylinder 60"  60" 

12.  HAND.     The  engine  shall  be  right  hand,  that  is,  when  standing  at  the  high  pressure  cylinder  and 

looking  toward  the  shaft,  the  wheel  will  be  on  the  right  and  the  low  pressure  cylinder  on  the 
right  of  the  wheel. 

13.  WHEEL.    The  wheel  shall  have  40  grooves  for  1%"  rope  and  be  18  ft.  in  diameter. 

14.  CYLINDERS.    The  cylinders  shall  be  of  close-grained  cast  iron  strong  enough  to  withstand 

200  Ibs.  steam  pressure  per  sq.  in.,  after  being  rebored  ZA"  in  diameter  without  caus- 
ing the  tensile  strength  in  the  metal  to  exceed  3500  Ibs.  per  sq.  in. 
It  shall  be  lagged  with  85%  carbonate  of  magnesia  held  on  with  Russia  iron  covering. 
Provision  shall  be  made  on  the  cylinder  for  attaching  indicators,  and  an  indicator  re- 
ducing motion  shall  be  provided  as  part  of  the  engine.  The  cylinder  shall  be  provided 
with  drip  cocks.  The  steam  ports  shall  be  of  ample  size  to  allow  easy  and  quick  action 
of  the  steam. 

15.  VALVES.     The  cylinder  shall  be  provided  with  relief  valves  of  ample  size  and  at  suitable 

position  to  protect  the  engine  from  damage  due  to  water. 
Throttle  valve  shall  be  furnished  with  the  engine. 
The  steam  valves  shall  be  of  the  Corliss  type  with  separate  eccentrics  for  the  steam  and 

exhaust  valves. 


NOTES  ON  POWER  PLANT  DESIGN  169 

16.  GOVERNORS.     The  governor  for  the  engine  shall  be  of  the  flyball  type. 

17.  LUBRICATION.     Lubrication  shall  be  by  means  of  sight  feed  oil  cups  which  shall  be  accessibly 

located  and  shall  positively  and  continuously  supply  the  main  shaft  bearings,  crank  pins 
wrist  pins,  guides,  valve  parts,  etc.  with  oil.     These  oil  cups  shall  be  provided  with 
bottom  connections  piped  to  a  common  point  ready  for  connection  to  a  gravity  oiling 
system.     All  pipe  shall  be  semi-annealed  iron  pipe  size  brass  pipe.     All  brass  parts  shall 
be  polished  and  nickel  plated. 

Grease  cups  will  be  allowed  only  on  eccentrics. 

Two  Richardson  model  "M"  four-feed  oil  pumps  shall  be  furnished  for  the  cylinders. 

18.  WRENCHES  AND  DRAWINGS.    The  following  fittings  shall  be  furnished  with  the  engine: 

1  set  of  forged  steel  wrenches. 

Foundation  plans  for  setting  foundation  bolts. 

Drawings  showing  dimensions  of  engine  and  foundation. 

19.  PACKING.    The  piston  rod  shall  be  packed  with  ..............  metallic  packing  and  the 

valve  stems  with  ..............  metallic  packing. 

20.  BOLTS,  ETC.     Bolts,  nuts  and  screws  shall  be  of  the  United  States  standard. 

21.  FINISH.     The  engine  as  a  whole  shall  be  highly  finished,  all  exposed  metal  parts  polished  and 

castings  carefully  dressed  down,  filled  and  painted  with  the  best  quality  of  paint. 

22.  DRILLING.     All  flanges  shall  be  faced  and  drilled  in  accordance  with  Manufacturer's  Standard. 

23.  STEAM  CONSUMPTION.     The  engine  shall  consume  not  more  than  the  amounts  of  steam  shown 

below  for  each  load  when  running  at  a  speed  of  80  revolutions  per  minute  with  a  steam 
pressure  of  175  Ibs.  per  sq.  inch  above  the  atmosphere  at  a  temperature  as  indicated  below 
and  exhausting  against  a  back  pressure  of  17  Ibs.  per  sq.  inch  absolute.  The  steam  pres- 
sure shall  be  the  average  measured  just  outside  the  throttle  valve  and  the  back  pressure 
shall  be  measured  in  the  exhaust  pipe  near  the  engine. 

Steam  Consumption  in  Pounds  per  I.  H.  P. 
Load  I.  H.  P.  Saturated  Steam 


Full 

IK 

21.  ERECTION.  The  engine  shall  be  erected  by  the  Contractor  on  foundation  furnished  by  the 
Purchaser.  After  the  engine  arrives  at  destination  the  Contractor  agrees  to  push  the 
erection  through  with  all  reasonable  promptness,  working  a  full  day  force.  The  engine 
is  to  be  erected  ready  for  operation  within  30  days  after  its  arrival  at  destination. 

25.  DESIGN,  MATERIAL  AND  WORKMANSHIP.     The  design  shall  provide  ample  bearing  surfaces, 

abundant  lubrication  and  strong  rugged  parts  and  shall  insure  safe,  reliable  and  econo- 

mical operation,  and  without  undue  heating  or  vibration. 
The  material  and  workmanship  shall  be  the  best  of  their  respective  kinds.     The  Contractor 

shall  furnish,  without  charge,  f  .  o.  b  ...............  a  duplicate  of  any  part  that  may 

prove  defective  in  material  or  workmanship  within  one  year  after  the  engine  has  been 

started.     All  nuts  on  cylinder  heads,  bonnets  and  other  parts  which  are  subject  to  re- 

moval shall  be  case-hardened. 
All  connections  about  the  engine  shall  be  made  perfectly  tight  and  all  parts  of  the  engine 

made  as  accessible  as  possible  and  capable  of  ready  removal  for  repair  or  replacement. 

All  parts  of  the  engine  subject  to  wear  shall  have  means  provided  for  taking  up  such 

wear.     All  interchangeable  parts  shall  be  machined  to  gauge. 

26.  DRAWINGS  AND  DATA.     Bidder  shall  submit  in  connection  with  his  proposal  an  outline 

drawing  to  scale  and  a  description  of  the  engine  he  proposes  to  furnish,  giving  in  detail 
the  design  of  cylinder,  piston,  governor,  bearings  and  arrangement  made  for  removal 
of  parts  and  for  repairs. 


170  NOTES  ON  POWER  PLANT  DESIGN 

27.     ENGINE  DATA.     Bidder  shall  furnish  the  following  data  on  the  engine: 
FLOOR  SPACE 

Length ft inches 

\Yidth   ft.     inches 

Height ft inches 

PIPING 

H.  P.  Cyl.  L.  P.  Cyl. 

Steam    inches 

Exhaust    inches 

VALVES 

Type  of  steam  valves 

Area  admission  ports    sq.  in. 

Area  exhaust  ports   . . .  .sq.  in. 

CONNECTING  RODS 

Type   

Length inches 

BEARINGS 

Diameter  main  bearings 

Length  main  bearings 

Diameter  crank  pin       H.  P.    .  , L.  P 

Length  crank  pin  H.  P L.  P 

Diameter  wrist  pin        H.  P L.  P 

Length  wrist  pin  H.  P L.  P 

Diameter  of  shaft  

Dimensions  of  cross-head  shoes    

GOVERNOR 

Type  of  governor  

BELT  WHEEL 

Diameter  18  ft.  0  inches 

Width  of  face     .  56  inches 

WEIGHTS 

Weight  of  heaviest  part Ibs. 

Weight  of  fly-wheel  Ibs. 

Shipping  weight  of  engine Ibs. 

Finished  weight  of  engine    Ibs. 


NOTICE  TO  CONTRACTORS 
Steam  Driven  Centrifugal  Pumping  Unit  for  the  City  of. 


Sealed  proposals  and  bids  for  furnishing  to  the  City  of Mass., 

and  installing  in  the St.,  Pumping  Station  of  the  City  of 

a  steam  turbine  driven  centrifugal  pumping  outfit,  as  hereinafter  described,  will  be  received  by 

the  Commission  of  Water  and  Water  Works  of at  the  City  Hall, 

Mass.,  until  12M,  September ,  1913. 

Bids  must  be  made  in  duplicate. 

Each  bidder  must  leave  with  his  bid  a  properly  certified  check  for  the  sum  of  two  thousand 

dollars  ($2,000)  payable  to  the  order  of  the  City  of ,  which  check  will  be  returned  to  the 

bidder  unless  forfeited  as  hereinafter  provided. 

A  bond  will  be  required,  for  the  faithful  performance  of  the  contract,  in  the  sum  of  ten  thousand 
dollars  ($10,000)  of  an  approved  surety  company  doing  business  in  Massachusetts. 

The  bidder  is  requested  to  name  the  surety  company  which  will  sign  his  bond  in  case  the  con- 
tract is  awarded  him. 


NOTES  ON  POWER  PLANT  DESIGN  171 

If  notice  of  the  acceptance  of  the  bid  shall,  within  twenty  days  after  September , 

1913,  be  given  to  the  bidder  by  the  Commissioner  of  Water  and  Water  Works  of !*.!*!"!, 

the  bond  must  be  furnished  within  six  days  (Sunday  excepted)  after  such  notification;  and  in 
case  of  the  failure  of  the  bidder  after  such  notification  to  furnish  the  bond  within  said  time  the 
bid  shall  be  considered  as  abandoned  and  the  certified  check  accompanying  the  bid  shall  be  for- 
feited to  the  city. 

Each  bidder  is  to  furnish  with  his  bid  detailed  description  and  specifications  covering  the  appar- 
atus he  purposes  to  install. 

He  is  to  give  also  the  duties  (duty  is  here  considered  as  the  foot-pounds  of  water  work  done 
per  million  British  Thermal  Units)  he  will  guarantee. 

First  considering  the  steam  used  by  the  steam  turbine  alone  without  including  the  steam  used 
by  either  wet  or  dry  pumps  used  in  connection  with  the  condensing  outfit,  and 

Second  including  the  steam  used  by  these  pumps  with  the  turbine  steam.  The  guarantees 
of  duty  to  be  made  on  a  pressure  at  the  throttle  of  125  Ibs.  gage  and  on  steam  containing  not  more 
than  one  and  one-half  per  cent  moisture. 

The  temperature  of  the  returns  to  the  boiler  to  be  taken  the  same  as  the  temperature  of  the 
condensed  steam  leaving  the  condenser.  If  the  exhaust  steam  from  the  wet  and  dry  pumps  is 
sent  through  a  feed  water  heater  and  used  to  heat  the  steam  condensed  from  the  turbine  on  its 
way  to  the  boiler,  the  temperature  of  the  returns  will  be  taken  as  the  temperature  of  this  feed 
water.  The  temperature  of  the  suction  water  to  be  taken  at  70°.  The  conditions  as  to  head  and 
capacity  to  be  taken  as  hereinafter  outlined. 

Each  ^  bidder  is  to  furnish  dimensioned  drawings  giving  the  general  outside  measurements 
of  the  entire  apparatus  when  assembled  together  with  such  drawings  or  cuts  as  may  be  necessary 
to  show  the  construction  of  his  apparatus. 

The  one  to  whom  the  contract  is  awarded  is  to  furnish  the  city  with  a  working  drawing  of 
the  foundation  (to  be  built  by  the  City)  and  complete  working  drawings  of  the  turbine  centri- 
fugal pumps  and  condensing  outfit  complete. 

The  bidder  is  to  guarantee  that  all  bearings  and  reduction  gears  if  used  will  be  continuously 
lubricated  and  will  run  continuously  without  over-heating. 

The  bidder  is  to  agree  to  make  at  his  own  expense  all  repairs  which  may  be  made  necessary 
through  original  faulty  construction,  design  or  workmanship  for  a  period  of  six  months  after  the 
unit  goes  into  regular  service. 

Neither  experimental  nor  unusual  types  of  apparatus  will  be  considered. 

Each  bidder  must  be  prepared  to  prove  to  the  satisfaction  of  the  Commissioner  that  he  has 
previously  installed  units  of  the  type  he  purposes  to  furnish  and  he  shall  state  where  such  units 
are  in  successful  operation. 

The  bidder  must  state  the  general  type  design  and  builders  name  of  any  part  of  the  unit  which 
is  not  built  at  the  works  of  his  own  company. 

The  bidder  must  give  the  date  of  delivery  and  the  time  required  for  the  erection  of  the  com- 
pleted plant. 

Payments  will  be  made  as  follows :  Fifty  per  cent  of  the  contract  price  ten  days  after  the  de- 
livery of  the  turbine,  pumps,  condensers,  and  accessories  at  the  pumping  station  and  the  balance 
due  the  contractor  ten  days  after  the  acceptance  of  the  unit  by  the  City. 

The  Commissioner  reserves  the  right  to  reject  any  or  all  bids  or  to  award  the  contract  as  he 
deems  best. 

The  duty  guaranteed,  the  general  design  and  accessibility  of  the  parts,  together  with  the  cost, 
will  be  considered  in  awarding  this  contract. 

Bids  in  which  the  duty  guaranteed  per  1,000,000  British  Thermal  Units  including  the  steam 
used  by  the  condensing  apparatus,  falls  below  92,000,000  foot-pounds  will  not  be  considered. 

The  bidder  will  submit  his  bid  and  his  specifications  on  his  own  printed  forms  and  will  add  to 
the  same  the  following: 

The  Contractor  will  indemnify  and  save  harmless  the  City  from  all  claims  against  the  City 
by  mechanics,  laborers,  and  others,  for  work  performed  or  materials  furnished  for  carrying  on  the 
contract. 

The  Contractor  will  indemnify  and  save  harmless  the  City,  its  agents  and  employees,  from  all 


172  NOTES  ON  POWER  PLANT  DESIGN 

suits  and  claims  against  it  or  them,  or  any  of  them,  for  damages  to  private  corporations  and  indi- 
viduals caused  by  the  construction  of  the  work  to  be  done  under  this  contract;  or  for  the  use  of  any 
invention,  patent,  or  patent  right,  material,  labor  or  implement  by  the  contractor,  or  from  any 
act,  omission  or  neglect  by  him,  his  agents,  or  employees,  in  carrying  on  the  work;  and  the  Con- 
tractor agrees  that  so  much  of  the  money  due  to  him  under  this  contract  as  may  be  considered 
necessary  by  tfie  Commissioner  may  be  retained  by  the  City  until  all  such  suits  or  claims  for  damages 
as  aforesaid  shall  have  been  settled  and  evidence  to  that  effect  furnished  to  the  Commissioner. 

The  Contractor  agrees  to  do  such  extra  work  as  may  be  ordered  in  writing  by  the  Commis- 
sioner, and  to  receive  in  payment  for  the  same  its  reasonable  cost  as  estimated  by  the  Commis- 
sioner plus  fifteen  per  cent  of  said  estimated  cost. 

The  Contractor  agrees  to  make  no  claims  for  compensation  for  extra  work  unless  the  same 
is  ordered  in  writing  by  the  Commissioner. 

The  Contractor  still  further  agrees  that  the  Commissioner  may  make  alterations  in  the  work, 
provided  that  if  such  changes  increase  the  cost,  the  contractor  shall  be  fairly  remunerated  and  in 
case  they  diminish  the  cost  the  proper  deduction  from  the  contract  price  shall  be  made  —  the  amount 
to  be  paid  or  deducted  to  be  determined  by  the  Commissioner. 

GENERAL  DESCRIPTION  OF  PUMPING  UNIT 

A  steam  driven  turbine  either  directly  connected  to  a  centrifugal  pump  or  connected  through 
reduction  gears  and  having  a  smaller  stage  centrifugal  connected  by  friction  clutch  or  other  suit- 
able device  to  the  end  of  the  pump  shaft  or  to  one  end  of  the  turbine  shaft  all  mounted  on  a  suit- 
able bed  plate  is  to  be  installed  together  with  a  water  works  type  condenser  and  necessary  wet  and 

dry  pumps  in  the St.  Pumping  Station  of  the  City  of A  feed  water 

heater  using  the  exhaust  steam  of  the  wet  and  dry  pumps  may  be  installed  by  the  contractor  (the 
one  to  whom  the  contract  is  awarded  is  hereinafter  designated  as  the  Contractor)  if  hereby  he  is 
able  to  increase  the  duty  by  raising  the  temperature  of  the  returns. 

This  equipment  is  to  be  put  in  the  ell  at  the  back  of  the  building  which  ell  is  now  used  as  a 
coal  pocket  and  storage  room.  There  is  now  a  large  outside  door  at  the  end  of  the  ell  leading  from 
the  back  yard  into  the  basement  of  this  building.  Another  large  door  located  over  this  basement 
door  at  the  level  of  the  present  engine  room  floor  is  to  be  made  by  the  city.  The  turbine  will  have 
to  be  taken  in  through  this  new  door  and  the  condensing  equipment  through  the  basement  door. 

This  outfit  is  to  be  erected  and  installed  by  the  Contractor  on  a  foundation  built  by  the  City 
in  accordance  with  drawings  furnished  by  the  Contractor.  (Foundation  bolts  are  to  be  furnished 
by  the  Contractor:)  The  Contractor  is  to  temporarily  strengthen  any  floors,  coal  pockets,  etc. 
he  may  move  his  machinery  over  and  to  take  all  responsibility  during  the  erection  of  the  machinery. 
Under  no  circumstances  is  the  operation  of  the  pumping  station  to  be  interfered  with. 

The  City  will  bring  steam  to  the  throttle  of  the  turbine.  The  throttle  valve  and  safety  throttle 
are  to  be  furnished  and  erected  by  the  Contractor.  The  City  will  connect  the  "suction"  pipe  with 
the  intake  of  the  condenser  and  will  make  all  connections  to  the  force  mains  back  to  the  discharge 
end  of  the  centrifugals.  In  preparation  for  tests  of  this  unit  the  City  will  install  a  Venturi  meter 
in  each  of  these  force  mains.  The  Contractor  is  to  pipe  the  condensed  steam  back  to  the  boiler 
feeding  apparatus  and  to  make  all  other  connections,  not  specifically  referred  to. 

The  Contractor  is  to  provide,  connect,  and  put  in  place  suitable  &%"  polished  brass  gages 
with  gage  cocks  as  follows,  all  mounted  on  a  gage  board  of  mahogany  or  stone  fastened  to  the 
wall  of  the  room  at  some  point  to  be  designated  by  the  chief  engineer  of  the  station. 

Gage  for  pressure  at  throttle  to  be  divided  to  150  Ibs.  by  one  pound  marks. 

Gage  pressure  in  condenser:  this  to  be  a  combination  pressure  and  vacuum:  20  Ibs.  pressure. 

Gage  for  measuring  pressure  in  force  mains  of  large  centrifugal:    120  Ibs.  by  1  pound  marks. 

Gage  for  measuring  pressure  in  force  mains  of  small  centrifugal :   150  Ibs.  by  1  Ib.  marks. 

Gage  for  showing  pressure  of  water  at  intake  to  condenser:    50  Ibs.  by  1  pound  marks. 

A  clock  in  a  case  like  the  gages  is  to  be  furnished  by  the  Contractor  and  mounted  on  this  gage 
board. 

The  Contractor  is  also  to  provide,  connect,  and  put  in  place,  a  mercury  column  for  measuring 
the  vacuum  in  the  condenser  and  thermometers  in  suitable  wells  for  determining  the  temperature 


NOTES  ON  POWER  PLANT  DESIGN  173 

of  the  water  entering  the  condensers,  the  temperature  in  each  force  main  and  the  temperature  of 
the  returns  from  the  condenser  to  feed  pumps. 

Water  comes  to  these  pumps  at  what  has  been  called  the  "suction"  side  under  a  static  head  of 
about  23  feet,  the  head  depending  upon  the  level  in  Breed's  Pond.  In  making  calculations  for 
duty  an  average  value  of  the  static  head  of  23  feet  at  the  level  of  the  main  floor  in  the  present  sta- 
tion may  be  assumed.  The  pipe  leading  from  Breed's  Pond  to  the Street  Station  is  about 

one-half  mile  in  length  and  is  36"  in  diameter  for  the  first  third  of  the  distance  and  30"  for  the 
remaining  two-thirds  of  the  distance.    There  are  four  elbows  in  this  30"  line. 

The  centrifugal  directly  connected  or  connected  through  reduction  gears  to  the  turbine  shaft 
is  to  discharge  13,000,000  U.  S.  gallons  in  24  hours  into  a  30"  force  main  about  one-half  mile  long  - 
practically  a  straight  run  of  pipe.     The  static  pressure  at  the  level  of  the  station  floor  of  the  main 
station  is  60  Ibs.     The  present  pumping  outfit  is  discharging  water  through  this  pipe  at  the  rate 
of  10,000,000  gallons  in  24  hours. 

The  stage  centrifugal,  connected  to  the  turbine  shaft  or  pump  shaft  by  a  friction  clutch  or  other 
suitable  device  is,  to  deliver  2,000,000  U.S.  gallons  in  24  hours  to  a  stand  pipe  through  about  one- 
half  mile  of  pipe;  the  first  half  of  which  is  16"  diameter  and  the  last  half  12"  diameter;  all  of  cast 
iron.  The  static  pressure  at  the  level  of  the  station  floor  of  the  main  station  is  105  Ibs.  Drawings 
of  the  pipe  lines  can  be  seen  at  the  office  of  the  City  Engineer,  City  Hall, ,  Mass. 

The  two  pumps  will  be  run  together  the  greater  part  of  the  time,  the  high  pressure  pump  con- 
nected and  disconnected  by  means  of  a  clutch  or  other  suitable  device  without  stopping  the  turbine. 

The  water  coming  from  Breed's  Pond  to  the x. Street  Station  varies  in  tem- 
perature from  35°  to  80°.  A  temperature  of  70  degrees  'seems  a  fair  average.  The  boilers  now 
installed  are  to  furnish  the  steam  for  this  unit.  These  boilers  are  of  the  horizontal  Multitubular 
type;  two  in  number  working  at  125  Ib.  gage.  The  steam  from  these  boilers  may  be  considered 
to  contain  not  more  than  1J^  per  cent  moisture.  The  condenser  is  to  be  made  strong  enough 
to  stand  with  safety  105  Ib.  gage  pressure  on  the  water  side  and  20  Ib.  gage  pressure  on  the  steam 
side. 

A  2"  safety  valve  with  whistle  is  to  be  attached  to  the  steam  side  of  the  condenser. 

The  turbine  is  to  be  provided  with  a  safety  throttle  quick  operating  trip  or  other  suitable 
device,  satisfactory  to  the  commissioner  to  prevent  speeding. 

The  turbine  is  to  be  provided  with  an  outboard  exhaust  through  a  water  sealed  automatic 
relief  valve.  The  discharge  from  this  valve  to  be  carried  by  means  of  spiral  riveted  pipe  through 
the  roof.  The  opening  made  in  the  roof  for  this  pipe  is  to  be  properly  flashed  with  copper  and 
made  tight  against  rain  and  snow. 

To  allow  for  expansion  there  is  to  be  a  flexible  connection  in  the  piping  between  the  turbine 
and  the  condenser. 

The  pump  impellers  are  to  be  of  bronze  on  suitable  non-corrosive  material  and  unbalanced 
end  thrust  on  the  impellers  to  be  avoided  as  far  as  is  possible. 

The  impeller  shafts  are  to  be  protected  from  corrosion  by  removable  sleeves  of  composition. 
Composition  packing  glands  and  bronze  studs  are  to  be  provided  for  the  pumps. 

The  contractor  is  to  paint  all  machinery  and  piping  erected  by  him.  Such  castings  as  are  in 
sight  from  the  floor  of  the  engine  room  are  to  be  made  smooth,  nicely  fitted  at  all  joints  and  flanges, 
filled  with  a  proper  paint  filler  and  painted  and  striped  in  such  colors  as  the  commissioner  may 
direct. 

The  Contractor  is  to  remove  all  blocking,  tools  or  other  material  used  by  him  in  erecting  and 

installing  his  work  and  to  remove  all  debris  of  any  nature,  in  and  around  the Street 

Pumping  Station,  produced  by  him  in  carrying  out  this  contract. 


174  NOTES  ON  POWER  PLANT  DESIGN 

SPECIFICATIONS  FOR  AND  DESCRIPTION  OF  PUMPING  UNIT  FOR 

LOCATION.  The  pumping  unit  is  to  be  installed  in  a  new  building  distant  about  500  feet  north 
from  the  pumping  station  on Pond  now  supplying  the  City  of 

FLOOR  LEVEL.  The  building  will  be  located  on  the  shore  of  the  pond.  The  pump  room  floor  being 
from  4  to  7  feet  above  the  level  of  full  pond. 

PUMP  MOTOR.  The  pump  is  to  be  either  a  single  or  two  stage  centrifugal,  driven  by  a  4000  volt 
three  phase,  60  cycle  alternating  current  motor  of  the  external  resistance,  slip  ring  type  com- 
plete with  device  for  lifting  brushes  and  short  circuiting  rings  after  the  pump  is  up  to  speed, 
and  all  necessary  starting  equipment. 

MOTOR.  The  motor  must  be  so  designed  that  the  starting  current,  under  given  load,  will  not 
exceed  full  load  running  current. 

MOTOR  CHARACTERISTICS.  The  temperature  rise  of  the  motor  when  operating  at  normal  rating 
with  a  room  temperature  of  25°  C.  is  not  to  exceed  40°  C. 

ELECTRICAL  SWITCHBOARD.  A  switchboard  of  slate  with  dull  black  finish  with  the  following 
equipment  is  to  be  furnished  and  erected,  all  meters  in  black  finish. 

(1)  One  voltmeter  with  scale  calibrated  to  show  4000  volts. 

(2)  One  indicating  watt  meter. 

(3)  One  ammeter  with  switch  to  show  current  on  any  of  the  three  phases. 

(4)  One  kilowatt  hour  meter. 

(5)  Suitable  testing  terminals  to  enable  check  to  be  made  on  these  instruments. 

(6)  Available  space  for  the  instruments  of  the Electric  Light  Co.  which  will 

be  one  kilowatt  hour  meter  and  suitable  testing  terminals. 

(7)  Complete  switch-operating  mechanism  and  mounting  for  all   switches   necessary 

for  starting  and  controlling  the  motor.     The  oil  circuit  breaker  to  be  of  remote 
mechanical  control  type. 

(8)  Necessary  current  and  potential  transformers  for  preceding  equipment;  also  available 

space  and  mounting  for  the  necessary  current  and  potential  transformers  fur- 
nished by  the Electric  Light  Co. 

(9)  A  125-volt  switch  to  control  electrically  operated  discharge  valve  if  such  electrically 

operated  valve  is  used;  provision  shall  also  be  made  for  125  volt  lighting. 

LIGHTNING  PROTECTIVE  APPARATUS.  In  addition  to  the  preceding  the  following  are  to  be  fur- 
nished and  separately  mounted:  One  complete  lightning  arrester  and  choke  coil  outfit  for 
one  3-phase  4000  volt  circuit,  (Y  connected,  neutral  grounded  at  generating  plant  only,  through 
low  resistance);  also  suitable  disconnecting  switches  for  the  lightning  arresters  and  incoming 
circuit  respectively. 

CIRCUIT  BREAKER.  One  oil  circuit  breaker  with  inverse  time  limit  overload  relay  and  no-voltage 
release,  with  remote  mechanical  control. 

Bus  WORK  AND  WIRING.  All  bus  work  and  wiring  necessary  for.  connecting  the  motor  to  the 
switchboard  and  to  power  wires  on  the  outer  wall  of  the  pump  house,  consisting  of  copper 
conductors,  clamps,  insulators,  pins  and  pipe  frame-work  and  other  details  necessary  for  the 
successful  operating  of  the  equipment,  are  to  be  furnished  and  installed  by  the  contractor. 

Power  wires  outside  of  the  pump  house  are  to  be  installed  by  the Electric 

Light  Co. 

PUMP  CAPACITY.  The  centrifugal  pump  is  to  discharge  8,000,000  U.  S.  gallons  in  24  hours  from 
a  pump  well  with  water  at  grade  127,  through  about  2180  feet  of  new  36"  cast  iron  pipe  to  a 
standpipe  with  water  at  grade  305.  There  is  to  be  a  hydraulically  or  an  electrically  operated 
valve  and  a  check  valve  between  the  pump  and  the  36"  main.  These  valves  are  to  be  fur- 
nished and  installed  by  the  city. 

HEAD.  This  36"  pipe  will  receive  an  additional  8,000,000  gallons  in  24  hours  from  a  second  unit 
in  the  same  pumping  station  or  from  another  station  approximately  500  feet  away.  This 
fact  fe  to  be  noted  in  considering  the  total  head  the  pump  is  to  work  against. 

IMPELLER  END  THRUST.  The  pump  impeller  is  to  be  of  bronze  or  suitable  non-corrosive  material, 
and  unbalanced  end  thrust  on  the  impeller  is  to  be  avoided  as  far  as  possible.  The  pump 


NOTES  ON  POWER  PLANT  DESIGN  175 

impeller  and  the  pump  casing  shall  be  provided  with  bronze  renewable  wearing  rings  so  that 
they  may  be  readily  replaced  if  necessary. 

IMPELLER  SHAFTS.  The  impeller  shafts  are  to  be  protected  from  corrosion  by  removable  sleeves  of 
composition.  Composition  packing  glands  and  bronze  studs  are  to  be  provided  for  the  pumps; 
stuffing  boxes  on  ends  of  pump  shall  be  provided  with  water  seals. 

PRIMING  DEVICE.  The  pump  is  to  have  a  water  ejector  or  other  device  capable  of  removing  air 
from  the  pump,  in  priming,  in  a  period  of  five  minutes. 

DISCHARGE  VALVE.  A  hydraulically  or  electrically  operated  valve  in  the  discharge  pipe  of  the 
pump  and  not  over  20  feet  from  the  discharge  outlet  of  the  pump  will  be  installed  by  the  City 
and  all  necessary  piping,  valves  or  wiring  and  switches  needed  for  the  operation  of  this  valve 
are  to  be  furnished  and  connected  up  by  the  contractor.  This  valve  will  be  closed  with  the 
pump  running  at  full  speed  preparatory  to  shutting  down  the  unit. 

PUMP  CHARACTERISTICS.  The  Contractor  must  submit  with  his  bid  curves  showing  the  char- 
acteristics of  the  pump  he  proposes  to  furnish.  He  must  guarantee  also  the  efficiency  of  his 
pump  at  8,000,000  gallons  capacity  when  working  under  the  total  head  (previously  explained). 
The  pump  shall  be  carefully  tested  before  it  leaves  the  manufacturer's  shop  to  show  that  the 
efficiency  guaranteed  has  been  obtained.  A  certified  test  shall  be  submitted  for  the  approval 

of  the Water  Board  before  shipment  is  made  and  notice  10  days  previous  to  test 

shall  be  sent  to  the Water  Board  so  that  it  may  be  present  if  it  desires. 

Should  the  efficiency  of  the  pump  as  determined  by  the  test  fall  below  that  guaranteed, 

the Water  Board  may  reject  the  pump  or  at  its  option  may  accept  the  pump  at 

such  reduction  in  the  original  contract  price  as  the  city  of niay  suffer  in  monetary 

loss  during  a  period  of  eight  years  through  the  lower  efficiency. 

The  Contractor  shall  furnish  the Water  Board  with  the  necessary  facili- 
ties for  carefully  inspecting  the  apparatus  during  the  process  of  manufacture. 

FOUNDATION.    The  foundation  for  the  unit  will  be  erected  by  the  city  in  accordance  with  draw- 
.     ings  to  be  furnished  by  the  contractor.     The  contractor  is  to  supply  all  foundation  bolts 
and  plates.    The  Contractor  is  to  furnish,  erect  and  connect  the  unit  complete  up  to  the 
discharge  flange  of  the  pump ;  also  to  make  necessary  and  suitable  connections  for  the  opera- 
tion of  the  hydraulically  or  electrically  controlled  valve  in  the  discharge  pipe. 

AUXILIARY  APPARATUS.  The  Contractor  is  to  furnish,  erect,  wire  up  and  make  all  necessary 
connections  to  such  auxiliary  apparatus  as  may  be  required  for  the  quick  and  successful  oper- 
ation of  his  unit. 

WRENCHES.  The  Contractor  is  to  furnish  all  special  wrenches  or  tools  required  in  assembling  or 
in  dismantling  either  the  pump  or  the  motor. 

GAGES  AND  PANEL.  The  Contractor  to  provide  a  slate  panel,  dull  black  finish,  matching  the 
electrical  board  and  mounted  alongside  same,  containing  the  following:  A  seven  day  clock 
mounted  in  a  brass  gage  case,  "black  finish;  a  10"  dial  brass  mounted  suction  gage  and  a  10" 
dial  brass  mounted  delivery  gage, —  these  being  connected  to  the  suction  and  delivery  pipes 
respectively.  These  gages  to  be  marked  hi  feet,  pounds,  or  inches  of  mercury  as  may  be  re- 
quested by  the Water  Board,  and  the  cases  given  a  black  finish. 

PAINTING.  The  Contractor  is  to  paint  all  machinery  and  piping  erected  by  him.  Such  castings 
as  are  in  sight  from  the  floor  of  the  pump  room  are  to  be  made  smooth,  nicely  fitted  at  all 
joints  and  flanges,  filled  with  a  proper  paint  filler  and  painted  and  striped  in  such  colors  as  the 
Water  Board  may  direct. 

DEBRIS.     The  Contractor  is  to  remove  all  blocking,  tools  or  other  material  used  by  him  in  erect- 
ing and  installing  his  work  and  to  remove  all  debris  of  any  nature  in  and  around  the  pumping 
.  station,  produced  by  him  in  carrying  out  this  contract,  at  least  100  feet  from  station  or  to 
such  place  as  he  may  be  directed. 

BIDS.  Bids  must  be  made  in  duplicate.  Each  bidder  must  leave  with  his  bid  a  properly  certi- 
fied check  for  the  sum  of  two  thousand  dollars  ($2000)  payable  to  the  order  of  the  City  of 

,  which  check  will  be  returned  to  the  bidder  unless  forfeited  as  hereinafter 

provided. 

BOND.  A  bond  will  be  required  for  the  faithful  performance  of  the  contract  in  the  sum  of  50% 
of  the  contract  price  with  a  surety  company  approved  by  the  mayor. 


176  NOTES  ON  POWER  PLANT  DESIGN 

The  bidder  is  requested  to  name  the  surety  company  which  will  sign  this  bond  in  case 
the  contract  is  awarded  him. 

If  notice  of  the  acceptance  of  the  bid  shall,  within  twenty  days  after  June  20th,  1914, 

be  given  to  the  bidder  by  the Water  Board,  the  bond  must  be  furnished  within 

ten  days  (Sunday  excepted)  after  such  notification;  and  in  case  of  the  failure  of  the  bidder 
after  such  notification  to  furnish  the  bond  within  said  time  the  bid  may  be  considered  as  aban- 
doned and  the  certified  check  accompanying  the  bid  may  be  forfeited  to  the  City. 

DESCRIPTION.  Each  bidder  is  to  furnish  with  his  bid  detailed  description  and  specifications  cover- 
ing the  apparatus  he  purposes  to  install. 

DRAWINGS.  '  Each  bidder  is  to  furnish  dimensioned  drawings  giving  the  general  outside  measure- 
ments of  the  entire  apparatus  when  assembled  together  with  such  drawings  or  cuts  as  may 
be  necessary  to  show  the  construction  of  his  apparatus. 

WEIGHTS.  The  individual  weights  of  the  rotor,  stator  and  pump  are  to  be  given  and  photographs 
of  typical  equipment  or  design  proposed  should  be  furnished  if  possible. 

WIRING.  The  bidder  is  to  attach  to  his  proposal  wiring  diagrams  and  detail  drawings  of  the  switch- 
board and  power  wiring. 

MOTOR  PERFORMANCE.  The  bidder  is  to  furnish  guarantee  as  to  motor  performance  when  operat- 
ing under  the  following  conditions : 

(1)  Speed  regulation  when  operating  between  no  load  and  full  load,  stating  load  at  which 
motor  is  rated. 

(2)  Power  factor  at  25,  50,  75,  100  and  125  per  cent  load. 

(3)  Momentary  overload,  per  cent  which  motor  will  carry  safely. 

(4)  Efficiency  based  on  room  temperature  of  25°  C.  at  the  following  percentages  of  load: 
(Respective  ultimate  temperatures  used  in  the  calculation  of  each  case,  to  be  stated) . 

25,  50,  75,  100  and  125  per  cent  load. 

(5)  Torque:    Give  pull  out  and  starting  torque  in  terms  of  full  load  torque. 

(6)  Temperature  rise  at  125  per  cent  normal  rating  for  two  hours  following  a  run  at 
normal  rating  of  sufficient  length  to  enable  the  motor  to  attain  a  constant  temperature. 

(7)  Certified  tests  covering  the  preceding  to  be  furnished  by  the  party  to  whom  the  con- 
tract is  awarded  before  the  apparatus  leaves  the  manufacturer's  shop.     Shipment  not  to 
be  made  until  approved  by  the Water  Board. 

Test  sheets  are  to  be  accompanied  by  a  description  of  the  method  of  test,  which  should 
as  far  as  possible  be  in  accordance  with  the  Standardization  Rules  of  the  American  Institute 

of  Electrical  Engineers.     If  doubt  arises  that  the  unit  has  not  come  up  to  test  the 

Water  Board  reserves  the  right  to  conduct  another  test  after  the  installation;  the  party  in  error 
being  responsible  for  payment  of  expenses  of  test. 

BEARINGS.  The  bidder  is  to  guarantee  that  all  bearings  will  be  continuously  lubricated  .and  will 
run  continuously  without  overheating. 

REPAIRS.  The  bidder  is  to  agree  to  make  all  repairs  which  may  be  made  necessary  through  original 
faulty  construction,  design  or  workmanship,  for  a  period  of  one  year  after  the  unit  goes  into 
regular  service,  at  his  own  expense. 

Neither  experimental  nor  unusual  types  of  apparatus  will  be  considered. 

UNITS  PREVIOUSLY  INSTALLED.  Each  bidder  must  be  prepared  to  prove  to  the  satisfaction  of 
the Water  Board  that  he  has  previously  installed  units  of  the  type  he  pro- 
poses to  furnish  and  he  shall  state  where  such  units  are  in  successful  operation. 

The  bidder  must  state  the  general  type,  design  and  builder's  name,  of  any  part  of  the 
unit  which  is  not  built  at  the  works  of  his  own  company. 

DELIVERY.  The  bidder  must  give  the  date  of  delivery  and  the  time  required  for  the  erection  of 
the  completed  plant. 

PAYMENTS.  Payments  will  be  made  as  follows:  One-third  of  the  contract  price  ten  days  after 
the  delivery  of  the  motor,  pump  and  accessories;  one-third  within  thirty  days  after  satis- 
factory and  successful  operation;  one-third  thirty  days  after  the  acceptance  of  the  unit  by 
the  city. 

ACCEPTANCE.     The Water  Board  reserves  the  right  to  reject  any  or  all  bids  or  to 

award  the  contract  as  it  deems  best. 


NOTES  ON  POWER  PLANT  DESIGN  177 

The  general  design  and  accessibility  of  the  parts,  together  with  the  cost  will  be  consid- 
ered in  awarding  this  contract. 

BIDDER  TO  ADD  TO  HIS  SPECIFICATIONS.    The  bidder  will  submit  his  bid  and  his  specifications 
on  his  own  printed  forms  and  will  add  to  the  same  the  following: 

That  he  will  indemnify  and  save  harmless  the  city  from  all  claims  against  the  city,  mechan- 
ics, laborers,  and  others  for  work  performed  or  material  furnished  for  carrying  on  the  contract. 

That  he  will  indemnify  and  save  harmless  the  city,  its  agents  and  employees,  from  all 
suits  and  claims  against  it  or  them  or  any  of  them,  for  damage  to  private  corporations  and 
individuals  caused  by  the  construction  of  the  work  to  be  done  under  this  contract;  or  for  the 
use  of  any  invention,  patent,  or  patent  right,  material,  labor  or  implement  by  the  contractor 
or  from  any  act,  omission  or  neglect  by  him,  his  agents,  or  employees,  in  carrying  on  the  work; 
and  that  he  agrees  that  so  much  of  the  money  due  to  him  under  this  contract  as  may  be  con- 
sidered necessary  by  the Water  Board  may  be  retained  by  the  city  until  all 

suits  or  claims  for  damages  as  aforesaid  shall  have  been  settled  and  evidence  to  that  effect 
furnished  to  the Water  Board. 

The  successful  bidder  will  be  required  to  furnish  a  certificate  to  the Water 

Board  certifying  that  the  men  employed  by  him  on  the  work  herein  set  forth  are  insured  under 
the  provision  of  the  Workmen's  Compensation  Act,  so-called,  of  Massachusetts. 

That  he  agrees  to  do  such  extra  work  as  may  be  ordered  in  writing  by  the 

Water  Board,  and  to  receive  in  payment  for  same  its  reasonable  cost  as  estimated  by  the 
. , Water  Board  plus  fifteen  per  cent  of  s'aid  estimated  cost. 

That  he  agrees  to  make  no  claim  for  compensation  for  extra  work  unless  the  same  is 
ordered  in  writing  by  the Water  Board. 

And  that  he  still  further  agrees  that  the Water  Board  may  make  altera- 
tions in  the  work  provided  that  if  such  changes  increase  the  cost  he  shall  be  fairly  remunerated 
and  in  case  they  diminish  the  cost,  the  proper  reduction  from  the  contract  price  shall  be  made, 
—  the  amount  to  be  paid  or  deducted  to  be  determined  by  the Water  Board. 

MASSACHUSETTS   INSTITUTE  OF  TECHNOLOGY 
Coal  Supply  —  1914-1915 

The  Massachusetts  Institute  of  Technology  invites  your  bid  on  its  supply  of  coal  for  the  forth- 
coming fiscal  year,  July  1,  1914-July  1,  1915,  on  the  following  terms: 

(1)  DELIVERY 

Daily,  as  called  for,  at  491  Boylston  St.,  rear  of  26  Trinity  Place,  Garrison  St.,  and  else- 
where, if  desired,  at  the  Technology  buildings. 

(2)  KINDS  AND  AMOUNTS 

(a)  No.  2  Buckwheat,  2700  tons,  more  or  less 

(b)  Semi-bituminous,  3800  tons,  more  or  less 

(3)  SPECIFICATIONS 

(a)  No.  2  Buckwheat  —  free  from  dust. 

(b)  Semi-bituminous  —  of  good  steaming  quality.     The  coal  offered  should  be  specified 
in  terms  of  moisture  "as  received,"  ash,  volatile  -matter,  sulphur  and  B.  T.  U.,  "dry  coal" 
basis,  which  values  become  the  standards  for  the  coal  of  the  successful  bidder.    The  trade 
name  of  the  coal  should  be  given. 

(4)  PRICES  AND  PAYMENTS 

(a)  No.  2  Buckwheat  —  payments  monthly  at  price  named. 

(b)  Semi-bituminous  —  payments  monthly  on  the  basis  of  price  named  in  bid,  corrected 
for  variations  as  to  heat  value,  ash  and  moisture  above  or  below,  as  follows: 

Heat  Value  —  On  a  "dry  coal"  basis,  no  adjustment  in  price  will  be  made  for  variations 
of  1%  or  less  in  the  number  of  B.  T.  U.'s  from  the  guaranteed  standard.  When  such  varia- 
tions exceed  1%,  the  adjustment  will  be  proportional  and  determined  as  follows: 

B.  T.  U.  delivered  coal,  "dry" 

— r>  ^  TT  ,  .  '    .  /    X  Bid  price  =  resulting  price. 

B.  T.  U.  specified  in  bid 


178 

Ash  —  On  a  "dry  coal"  basis,  no  adjustment  in  price  will  be  made  for  variations  of  1% 

or  less  above  or  below  the  per  cent  of  ash  guaranteed.     When  such  variation  exceeds  1%,  the 

adjustment  in  price  will  be  determined  as  follows: 

The  difference  between  the  ash  content  of  analysis  and  the  ash  content  guaranteed 
will  be  divided  by  2  and  the  quotient  multiplied  by  bid  price,  the  result  to  be  added  to 
or  subsracted  from  the  B.  T.  U.  adjusted  price  or  the  bid  price,  if  there  is  no  B.  T.  U. 
adjustment,  according  to  whether  the  ash  content  by  analysis  is  below  or  above  the  per- 
centage guaranteed. 
Moisture  —  The  price  will  be  further  adjusted  for  moisture  content  in  excess  of  amount 

guaranteed,  the  deduction  being  determined  by  multiplying  the  price  bid  by  the  percentage  of 

moisture  in  excess  of  the  amount  guaranteed. 

(5)  SAMPLING  AND  TESTING 

The  samples  of  coal  shall  be  taken  by  the  Institute  or  its  representative  and  no  other 
sample  will  be  recognized.  The  coal  dealer  or  his  representative  may  witness  the  operation 
of  the  sampling  if  so  desired.  Samples  of  the  coal  delivered  will  be  taken  by  the  Institute  or 
its  representative  from  the  wagons  while  being  unloaded.  Two  or  more  shovelfuls  of  coal 
shall  be  taken  from  each  wagon  load  and  placed  in  a  metal  receptacle  under  lock.  Not  less 
than  three  times  in  any  one  month  the  samples,  thus  accumulated,  shall  be  thoroughly  mixed 
and  quartered  in  the  usual  manner.  The  final  sample  is  to  be  pulverized  and  passed  through 
an  80-mesh  sieve.  A  part  of  the  final  sample  shall  be  put  aside  in  an  air-tight  jar  properly 
marked,  for  the  coal  dealer,  so  that  he  may  verify  results  if  he  so  desires. 

The  coal  shall  be  dried  for  one  hour  in  dry  air  at  a  temperature  between  104°  C.  and  105°  C. 

The  coal  shall  be  tested  by  the  Institute,  a  bomb  calorimeter  being  used.  Should  the 
coal  dealer  question  the  results,  a  sufficient  quantity  of  the  original  sample  is  to  be  furnished 
him  for  testing  if  he  so  requests  it. 

The  average  of  the  results  of  the  tests  made  each  month  shall  be  the  basis  for  determining 
the  price  to  be  paid  for  coal  delivered  during  that  month. 

(6)  LIMITS 

Should  the  heating  value  per  pound  of  dry  coal  fall  below  14,500  B.  T.  U.,  or  should  the 
moisture  exceed  3%,  or  the  ash  exceed  7%,  or  the  sulphur  1%,  or  the  volatile  matter  20%, 
the  agreement  may  be  terminated  at  the  option  of  the  Institute. 

(7)  THE  RIGHT  to  reject  any  or  all  bids  is  reserved  by  the  Institute. 


Cross-  Section. 


«— -Jib 


SECTIONAL  ELEVATION  OF  PORT  MORRIS    STATION. 


— Boston  Edison  L  Street  Power-House. 


.—Lots  Road,  Chelsea:  Sectional  Elevation. 


», — Quincy  Point  Power- House:  Elevation 


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